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Cold weather misfires and CEL

1M views 1K replies 281 participants last post by  AntonB 
#1 · (Edited)
So tis the season for the usual car runs rough on start up, misfires, CEL/MIL, stalling. Before you get too deep into this thread, I believe most of the data is relevant to the 325/330 models, or typical the 2.5L M52tu and 3.0L M54 engines also used in the E39 5 series and E85??Z4 series (however, it may be relevant to the 323/328 models as well, but part numbers will probably vary?), please check part number and application carefully before placing parts orders.

First suggestion to help you move in the proper direction is get your CEL/MIL codes read. Log and note the date, mileage and each trouble code. If there is Freeze Frame data, note this as well. Then clear codes, NOTE YOU WILL NEED AN ODBII SCAN TOOL TO CLEAR YOUR CODES, also NOTE IF YOU ARE NOT USING A BMW SPECIFIC SCAN TOOL (PEAKE, GT1, PA SOFT, CARSOFT, ETC.) YOU MAY ONLY GET A PARTIAL PICTURE OF WHAT CODES YOUR CAR MAY HAVE. The idea here is each time your CEL/MIL lights up, try to read, Log and and clear your codes ASAP. This will help you identify what code(s) show up first and will help you narrow your problem before other codes show up and may mislead you.

If you do not have a code reader or scan tool, many auto parts stores (Auto Zone, Advance, Pep Boys, O'Rielly, Fisher, etc.) will allow you to borrow one and usually use it in their parking lot.

As of Jan 2019 we have found OBDFusion and the VeePeak interface combination for either Android or iProducts tends to be rock solid and is one of the most cost effective and powerful OBDII Apps that also allows for Logging data.

If you have a smart phone or tablet, get an OBDII App and interface so you can read the codes along with Live/Realtime or Freeze Frame data then you will know exactly what is going on with the engine fuel management system.

The OBDFusion App and proper VeePeak interface from Amazon are less than $40 for both for iProducts, less than $20 for both for Android.

OBDFusion for Android is $4.99 from the Google Play Store.

For Android this lower cost standard Bluetooth interface in the link below works well, but DO NOT try to use this with iProducts.

https://www.amazon.com/Veepeak-Blue...=1487373393&sr=8-1&keywords=veepeak+bluetooth

OBDFusion, for the iProducts it is $9.99 from the Apple App Store.

For iProducts you NEED a LE Bluetooth adapter which are more expensive. VeePeak now offers a LE Bluetooth interface that is compatible with OBDFusion in the link below. While people have used the Wifi adapter, I would HIGHLY recommend NOT using Wifi with iProducts, brings a lot of baggage and stability issues.

https://www.amazon.com/Veepeak-OBDC...e=UTF8&qid=1504549087&sr=8-2&keywords=veepeak

Buy the interface you need NOW!

Please note that the bulk of this thread has to do with problems on cold start up and during idle situations. There have been a number of cases lately where codes P0171/P0174 are not triggered at idle, but at highway cruise speeds. I suggest you cover the bases with the very common solutions listed below, but if once you have cleared the obvious problems and if you are getting P0171/P0174 at highway cruise speeds only, then you are most likely not dealing with a standard intake or crankcase vacuum/air leak. I will be adding information to this thread in the near future for lean codes at highway cruise speeds[/COLOR]

IMPORTANT INFORMATION

As mentioned above, the bulk of this thread has to do with idle based problems, usually caused by vacuum/air leaks, but we have started to see a few cars that owners have addressed all the obvious vacuum/air leaks and they are still getting mostly Lean codes, many times without DME misfire codes. In a number of these instances the problems only show up during highway cruising situations, the CEL will not trigger during start up or any in town sub 45 MPH driving. But once the car is brought up to highway cruise type speeds, a few cars are still triggering the CEL along with P0171 & P0174. In many of these cases the problem has been with soft failed MAF's that are under reporting the amount of intake air, therefore causing the mixtures to be adjusted lean, then triggering Lean P0171 & P0174. So in some cases you may have a soft failure on a MAF where the engine is misfiring and running poorly and/or in a limp mode without any specific CEL or DME trouble codes.

Some cases we have seen soft failures on fuel pumps and/or fuel filters that either the pressure regulators are not working correctly, even restricted fuel filters with 80-120k miles of fuel passing through them. A few major telltale results of a soft failing fuel pump is running out of fuel while the fuel gauge indicates 1/4 tank and a moaning sound under the drivers floor board or along the driver side rocker panel, this is usually caused by the fuel pressure regulator vibrating due to low fuel volume and inconsistent fuel delivery from the fuel pump. The moaning can often be VERY loud and sounds like a wounded elephant. Some of the soft fail fuel pump failures are causing P0171/P0174 without misfire and may only happen off idle when cruising. Sometimes even causing idle surge and instability without triggering the CEL or codes. Please cover the basics and take care of simple things like spark plugs, fuel filter and engine vacuum caps and hoses before spending a lot of money on other parts. If you do not know the history on your spark plugs, air filter and fuel filter, it is probably time to change them!

FUEL PUMP ISSUES

This is not really part of the simple vacuum leak/hose problems that were originally outlined, but BEWARE there are soft failures on fuel pumps that can lead to intermittent hesitation, rough idle, misfires and stalling.

Suggest you check this link here for more info on fuel pump failures - https://forum.e46fanatics.com/showthread.php?t=929501&highlight=

A PM replacement of the pump, fuel filter and fuel pump relay may be a good idea. Parts cost if you do your homework should be under $200 and take about 1 hour. The best pump prices are from www.bmaparts.com from what we have seen lately. Fuel filter pricing on Amazon is pretty good as well.

Other items to possibly consider, but may not have been identified as actual causes of lean codes are as follows: camshaft timing may be out of spec possibly due to prior cylinder head removal and/or timing chain work, VANOS seals possibly casing camshaft timing to be off, throttle body/TPS issues. These are things to consider and to look into, many of these issues have not been proven to be a cause of the lean codes, however, just additional items to think about. Also keep in mind that pre Cat O2 sensor health is also important for proper reporting of fuel mixtures. And the last thing to think about is engine to body grounding. If for some reason the ground path between the engine and body/DME is questionable, you again may have incorrect reporting of sensor date, therefore possibly causing problems with CEL and DME trouble codes. So look at the charging Voltages and check the engine to body grounds while under the hood. Camshaft position sensors are also known weak points in these cars and they can also soft fail causing incorrect camshaft position feedback, thereby causing the VANOS to not work properly and possibly impact performance enough to cause Lean codes to be triggered.

But in any event, I would start with reading the DME trouble codes and uses these as clues, check all the obvious source so vacuum leaks, replace known problem hoses, gaskets and intake boots, then see where this all leads you. Additionally many maintenance related items should also be addressed before jumping into more costly and difficult sensor replacement.

Most of the problems I mention in this thread trigger one or more of the follow codes, but not limited just to these codes:

P0171 = Fuel Trim, Bank1 System Too Lean
P0174 = Fuel Trim, Bank2 System Too Lean
P1083 = Fuel Control Limit Mixture Too Lean (Bank 1, Sensor 1)
P1085 = Fuel Control Limit Mixture Too Lean (Bank 2, Sensor 1)
P1090 = Pre Catalyst Fuel Trim Too Lean Bank #1
P1091 = Pre Catalyst Fuel Trim Too Lean Bank #2
P0300 = Random/Multiple Cylinder Misfire Detected
P0313 = Misfire Detected Low Fuel Level
P1342 = Misfire During Start Cylinder 1
P1343 = Misfire Cylinder #1 with Fuel Cut-Off
P1344 = Misfire During Start Cylinder 2
P1345 = Misfire Cylinder #2 with Fuel Cut-Off
P1346 = Misfire During Start Cylinder 3
P1347 = Misfire Cylinder #3 with Fuel Cut-Off
P1348 = Misfire During Start Cylinder 4
P1349 = Misfire Cylinder #4 with Fuel Cut-Off
P1350 = Misfire During Start Cylinder 5
P1351 = Misfire Cylinder #5 with Fuel Cut-Off
P1352 = Misfire During Start Cylinder 6
P1353 = Misfire Cylinder #6 with Fuel Cut-Off
P0301 = Cylinder 1 Misfire Detected
P0302 = Cylinder 2 Misfire Detected
P0303 = Cylinder 3 Misfire Detected
P0304 = Cylinder 4 Misfire Detected
P0305 = Cylinder 5 Misfire Detected
P0306 = Cylinder 6 Misfire Detected
P0491 = Secondary Air Injection System Insufficient Flow (Bank 1)
P0492 = Secondary Air Injection System Insufficient Flow (Bank 2)
P0441 = Evaporative Emissions System Incorrect Purge Flow
P0455 = Evaporative Emissions System Leak Detected (Large Leak)
P0456 = Evaporative Emissions System Leak Detected (Very Small Leak)

Below are some of the MOST common problems/solutions. There may be other things that cause similar problems, but these are fairly easy to check visually, cheap and easy repairs. Many owners tend to just want to have a high priced single solutions like MAF, O2 sensors, ICV, Coils, Fuel Pumps, keep in mind that some of these items may be a contributing factor, however, it does not matter how many $100-$200 parts you throw on the car, if you have rubber hoses and gaskets leaking air, all the hard parts in the world will not solve your problems, they may help, but why not check the simple and cheaper things first, then check them off your list before you move forward. Except for the DISA O-ring, most of the other things can be visually inspected and tested very simply without a lot of dis-assembly. You can then rule these items in or out as potential problems within a few minutes if you know exactly what to look for.

Many of these problems are due to intake air leaks and/or crankcase air leaks of some sort, usually due to loose, damaged, broken or deteriorated parts, most likely rubber or plastic. Do not rule out crankcase leaks as the design of the engine keeps the crankcase under a small vacuum most of the time. A crankcase air leak is basically an intake air leak in these cars. The problem could be as simple as a dipstick not fully seated, a bad or loose oil fill car or a bad valve cover gasket or cracked valve cover that does not leak oil but can leak air/vacuum. Also in more extreme cases you can have vacuum leaks at the intake manifold to cylinder head connection. These gaskets have silicon rubber seals that can get heat set in the compressed state and leak only on cold start up situations.

A few ways to find and locate vacuum/air leaks is with a smoke tester (Internet search for more on smoke testers), using additional vacuum hose and using smoke inhaled from a cigarette or cigar, then blowing it into the vacuum hose to fill the intake or other vacuum lines, using a mechanics stethoscope with the transducer removed so you have open hose to you ears to attempt to locate a vacuum leak source while the engine is running, a 4 foot piece of hose to hold up to your ear to listen for vacuum leaks when the engine is running, and last but not least is a can of spray brake cleaner to spray and pinpoint vacuum leaks while the the engine is running. The spray brake cleaner will cause the engine RPM to increase slightly and smooth out when a leak is pinpointed. I have found via experience that very small and hard to find vacuum leaks, like where an intake manifold meets the cylinder head can be found much easily with spray brake cleaner than smoke testing or other methods. Also a note on smoke testing, many people swear by these, however, in practical terms, the smoke tester usually operate on very low pressure, usually 2-5 psi, they are usually only good for locating very obvious leaks that you should be able to find with visual inspection if you know where to look. I find that smoke testing may not show very difficult leaks like silicon gasketed surfaces such as the DISA or intake to cylinder head mating surfaces, this is where sometimes spray brake cleaner works much better. Be careful with spray brake cleaner on painted surfaces, breathing the fumes too much or getting it in your eyes due to splash back or air flow off the engine cooling fan. Use your head and be safe while working under the hood with the engine running, watch out for moving and hot parts, be aware of high Voltage ignition components and spraying flammable chemicals around!

Not in any specific order, but if you own an E46 (Actually almost any 6 cylinder BMW prior to the cut over to the e9x series models in 2005/2006), they are old enough now that these items should be replaced soon anyway. Please verify correct part numbers @ www.realoem.com to make sure you purchase and have the correct part numbers for your vehicle repair.

Here is a good link that has a complete DIY with pictures for most of the items listed below - https://forum.e46fanatics.com/showthread.php?t=643639&highlight=ccv

1. DISA Valve (sometimes referred to as an Adjuster Unit) #7 in this link - http://realoem.com/bmw/showparts.do?model=ET37&mospid=47720&btnr=11_2879&hg=11&fg=40. The DISA has a number of different failure modes, the DISA can have problems anywhere from vacuum leaks to catastrophic failure that may leave butterfly floating loose in the intake plenum and possibly the rear metal pivot pin could fall out and be sucked into once of the cylinders causing pretty severe engine damage.


SPECIAL NOTE ON THE REAR DISA PIN - The rear DISA pin can and will fall out depending on how badly the DISA butterfly plate is worn on the actuator shaft. This metal pin appears to be pressed into the rear of the butterfly and rotates with the butterfly plate. If the butterfly has become cracked or is overly loose on the actuator shaft, this metal pin (about 1/4" in diameter and about 13/16" long) could possibly become loose, fall out of the DISA assembly and work its way into a cylinder and may possibly cause severe engine damage. If you remove the DISA, immediately look for the rear metal butterfly pin and make sure it is still firmly pressed in. If you do not find the pin, check the intake VERY carefully for the pin and remove it if you find it. If you find the pin and it is loose in anyway, please remove the DISA flap and rear metal pin if you need to reinstall the existing, worn out DISA until you can purchase and install a new DISA


The first thing you want do is remove the DISA valve, pretty easy overall, remove the intake air filter box, upper intake boot and a few wire connectors and you are ready to access the DISA, you will need the Torx bit to actually remove the 2 DISA mounting screws. Once the DISA screws are removed, ease the DISA out of the intake, do not force it, there is only 1 angle that the DISA will likely come out and go back into the intake, it is not hard once you find the proper angle.

If the DISA valve slides out of the intake the first 1/4" easy, without much effort, or almost falls out, you will need a new O-ring!

Now that you have the DISA out of the intake, you need to check other functions to make sure you even want to re-use the DISA long term.

Special note for inspecting DISA valve, while you have the DISA out, inspect the DISA for proper operation. The DISA butterfly should be spring loaded in the open position and the butteryfly should not be overly loose or sloppy in the DISA shaft. You can also shake the DISA and it should not be noisy (new DISA will make absolutely no noise or rattle if shaken VERY hard). If you have any noise when shaking the DISA, something is most like worn and/or broken and you should consider a replacement DISA. Also the DISA rear pin can fall out into the engine and the DISA butterfly valve can fall off and get stuck in the intake possibly blocking the airflow to 1 or more cylinders, so it you remove the DISA and see no butterfly flap or rear metal pin, get worried and start looking for spare parts in the intake. If you are lucky the rear metal pin will be in the DISA groove in the intake.

Keep this in mind in case you suspect your car may have already had a replacement DISA, and if you have some strange performance issues, maybe someone left the old butterfly in the intake manifold if it fell off the original DISA??

The DISA is vacuum controlled and the small vacuum actuator on the end of the DISA is what actually moves the butterfly valve along with a control solenoid. Overall the DISA is a very ingenious device. The large body is actually vacuum reservoir. If look closely there is a very small hole near the butterfly valve this is the actual vacuum source. To verify if the vacuum actuator is still working and not leaking, close the DISA butterfly with your hand and then put your thumb over the opening that is opposite side of the electric connector on the solenoid. What should happen is the DISA butterfly will spring back open about 1/4" beyond the DISA frame. If the butterfly pops all the way back to the open position or slowly moves back to the default open position, then the vacuum actuator diaphragm is leaking and the DISA will not function correctly.

While there may be some sources that offer DISA "rebuild" kits, I would stay away from them personally. The butterfly valve and shaft are only part of the DISA, there is also an electrically controlled solenoid, actuator shaft seal and a vacuum diaphragm that actually moves the DISA valve and these parts can and will fail. The shaft/butterfly failure usually happens sometimes after the 100k mile mark, so if you car has the original DISA still, it is most likely ready for a replacement by now anyway. The vacuum diaphragm is more likely to fail than the solenoid and if the vacuum diaphragm fails you will end up with ANOTHER hard to find vacuum leak. There have also been a few reports of DISA vacuum actuators that test fine before the DISA repair kit was installed, but after removing the shaft and butterfly valve, after the vacuum actuator link was tweaked and twisted, the vacuum diaphragm was then cracked and no longer properly held vacuum. This is kind of expected from a decade old flexible rubber diaphragm, so just beware and be forewarned. If you are reading this thread, your car is clearly old enough now that if the butterfly is loose on the shaft or the DISA rattles when you shake it, just do yourself a favor and buy a new DISA and be done with your problem DISA for the next 7-10 years.

If you feel the DISA is physically in good shape and the vacuum diaphragm for the actuator is still in good shape and holds vacuum, then you may just need to replace the primary O-ring, which is not typically serviceable, however, you can get a red silicon replacement on for under $12 online or someone mentioned you might be able to match up something at your local parts store. Recommend a silicon O-ring as it is a bit softer than some of the harder rubber compounds and will tend to seal better with the plastic expansion and contraction over wide temperatures. I would be so inclined to put this replacement on a new DISA anyway as the DISA seal is only good for about 5 years/50k miles, after than you are on borrowed time. If for some reason you remove the DISA to replace the lower intake boot or do other work on the car, REPLACE the O-ring or you will be sorry once it gets below 40F. Trust me.

If you think your DISA should be replaced, following are some of the most common part number, but please check the part number before ordering a replacement for your vehicle. DISA prices online are between $175-$225 depending on the part number and the supplier. Prices change, however, check www.bmwmercedesparts.com for pricing as if this entry they have the 3.0 L DISA for $176.

DISA BMW part number - Please verify these via www.realoem.com to confirm proper application.
325/2.5L engines appear to use BMW Part #11617544806, this appears to have superseded an earlier BMW Part #11617502269
330/3.0L engines appear to use BMW Part #11617544805, this appears to have superseded an earlier BMW Part #11617502275
Both of the 325/330 DISA's have the injected or mold orange silicon main seal. SPECIAL NOTE - The 325 and 330 DISA appear to be very close in size, the main intake hole opening is the same size, however, the 325 DISA will fit into a 330 intake opening, but not the other way around. The 330 DISA is about 1/2" longer overall. Make sure you did not or do not end up with the 325 DISA in a 330 intake. I believe the 330 DISA will bottom out in the 325 intake before the flange meets the intake surface. As a point of reference, the last 7 digits of the DISA part number will be cast into the side of the DISA next to a BMW logo. So a 325 DISA should have either 7502269 for the original part up through 4/04 or 7544806 for the newer version used after 4/04. The 330/3.0L DISA should have either 7502275 for the original part up through 4/04 or 7544805 for the newer version used after 4/04.

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Taller (left side) DISA is for 3.0L engines, Shorter (right side) DISA is for 2.5L engines.



323/328 2.3L & 2.8L engines use DISA BMW part number - 11611440049, with the green removable O-ring. I have not confirmed for sure that the 2.3L/2.8L DISA has the part number cast into the side, but if it did, I assume it would have 1440049 after the BMW logo on the side of the DISA? Please verify part number and application.

Please verify part numbers @ www.realoem.com to verify proper part application for your vehicle!

If you feel your DISA is still serviceable, then I definitely suggest replacing the primary O-ring. Again, please measure your DISA and/or make sure when you order a replacement O-ring to specify your engine model as there are differences between the 323/328 & 325/330 series engines.

Note about the O-ring replacement, the 325/330 DISA has an orange molded/injected silicon seal in the groove, the 323/328 engines have a standard replaceable green O-ring. On the 325/330 you need to take a small screw driver and maybe a brass wire brush to scrape the groove clear of the original silicon before installing the new replacement O-ring. Then lube the O-ring with some silicon spray or clean light oil before reinstalling the DISA. The DISA will take some effort to seat it the last 1/4".

I do not suggest using any sort of sealer on the DISA O-ring area. There is an issue where the material needs to expand and contract to seal over temperature and any sort of sealer will not really work for the type of interface where this needs to seal in the inside of the hole in the intake manifold. What will happen is any sort of sealer will likely just make a mess that will need to be cleaned up once a proper O-ring has been installed.


PLEASE MAKE SURE YOU HAVE CLEARLY READ THE DISA SPECIAL NOTE ABOVE ABOUT THE REAR METAL BUTTERFLY PIN, WARNING, THIS PIN CAN FALL OUT ON EXTREMELY WORN DISA'S AND POTENTIAL CAUSE SEVERE ENGINE DAMAGE IF SUCKED INTO A CYLINDER


Sources for DISA O-ring

323/328 M52 Engines - Green removable O-ring

BMW Part #11617504543, this is a serviceable part for these engines.

http://www.ecstuning.com/BMW-E46-328i-M52_2.8L/Search/Disa/ES25713/ -

Your local auto parts suppliers may have something that fits?? Examples - Auto Zone, Advance, Pep Boys, O'Rielly, Fisher, but this may be a wild goose chase and it would probably be better to order the O-ring online so you will get something a bit closer in fit.

For the 325/330 M54 engines, the DISA O-ring is not a serviceable part, you have to remove the orange injected/molded silicon sealer and clean the groove out and install a replacement O-ring.

http://germanautosolutions.com/DISA_O-Rings.html

DISA O-rings for 325/330 engines have the following dimensions.

Some manufactures have an O-ring sizing chart. O-rings referenced as -136, -137, -138, -139 should all work. These sizes are 3/32" thick and range from 2" to 2 3/16" I.D.

Thickness - 3/32" (do not suggest anything thicker)
I.D. - 2" - 2 3/16"
O.D. - 2 3/16" - 2 3/8"
Preferred material - silicon, however, rubber may substitute

Thickness - 2.5 mm (do not suggest anything thicker)
I.D. - 51mm - 55 mm
O.D. - 55mm - 60 mm
Preferred material - silicon, however, rubber may substitute

DISA O-rings for the 323/328 engines have the following dimensions.This is for DISA's with the green, removable O-ring, not the orange molded seal. I also believe that the green O-ring DISA's are less problematic than the DISA's with the orange molded seal?

Again this is a BMW serviceable part, part number 11617504543.

Thickness - 1/8"
I.D. - 2"
O.D. - 2 1/4"
Preferred material - silicon, however, rubber may substitute

Thickness - 5.5 mm
I.D. - 51 mm
O.D. - 62 mm
Preferred material - silicon, however, rubber may substitute

Simple way to verify the proper O-ring thickness without having super expensive measuring systems is the following:

VERY, VERY simple way to measure the O-ring, it will cost you less than $0.10 to measure the O-ring accurately and you will not need to actually "spend" the $0.10.

If you buy an O-ring you want one that is 3/32" thick for the 325/330 applications, NOT 1/8" thick which many ebay sellers are shipping.

You will need 2 dimes to measure the O-ring thickness.

Toss the O-ring on a flat surface like a table, stack 2 dimes in the middle of the O-ring then use something flat like a card or ruler to lay across the O-ring, it should be almost exactly the thickness of the 2 dimes.

The thicker 1/8" O-ring which is the wrong one to use is the thickness of 2 quarters stacked.

Hope this helps people quickly determine if the have the proper thickness O-ring.

YouTube DISA Removal Video - http://www.youtube.com/watch?v=dhw6UpjhPXg contributed by SolidJake from the forum here.

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2. Lower Intake Boot, #6 in the this link - http://realoem.com/bmw/showparts.do?model=ET37&mospid=47720&btnr=13_0905&hg=13&fg=15, cracked or torn, usually at the small elbow connection point due to stress on the boot and the high under hood temperatures. About $20 depending on where you purchase it. Note that to really get at this, it is easier to take the DISA valve out to give you better access. Look very closely at the small flexible tube on the lower elbow as this is usually where the cracks occur. Its almost like you should just replace it anyway if it appears original as the rubber gets hard and cracks. A few notes, the hose clamps on the lower boot are very hard to reach. Many people cut the old boot to gain better access to the hose clamps. A 1/4" drive socket set with flex ratchet and a very long flat blade screw driver (12+") help here. Once hose clamp is loose, rotate then try to use the long screw driver to finish loosening the clamps. Also if you plan on replacing the upper intake boot, cut a slit along the plastic F connector so you do not break the connector trying to remove it from the original upper boot. Use silicon spray when installing the F fitting into the new upper boot.

Tools I use for the lower intake boot hose clamps - https://forum.e46fanatics.com/showpost.php?p=14120561&postcount=147 and I do all the work from under the hood, not under the car!

The parts numbers below are known to be for 325/330 engines, but again before you order parts for your car, please visit www.realoem.com and verify the proper part numbers for your application.

Lower boot, BMW part number - 13541435627 , this is the most common failed boot
Upper boot, BMW part number - 13541705209
F vacuum fitting, BMW part number - 13327503677

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3. CCV (Crank Case Vent) lower oil drain hose, #4 in this link - http://realoem.com/bmw/showparts.do?model=BW53&mospid=47707&btnr=11_2194&hg=11&fg=15, BMW Part #11157532649 or for cold climate BMW Part #11157532629 which is probably the best option for all cars, it just has more insulation to keep it from freezing as easily if there is a lot of condensation in the oil. Also on Amazon - http://www.amazon.com/11157532649-9..._2?s=automotive&ie=UTF8&qid=1327346039&sr=1-2
Connects between the dipstick tube and the bottom of the CCV. The connection to the bottom of the CCV is a bit tricky to unlatch blind, but it can be performed without taking anything but the air filter box out. I find if you get the end of the hose off the dipstick it makes it easier to rotate the snap fitting on the bottom of the CCV. I use a long (14-16") flat blade screw driver to help push off the CCV oil drain hose from the bottom of the CCV while I squeeze the release bail as it is VERY hard to squeeze the release bail and pull down at the same time from under the hood. It is not easy to get your hand down there, but it is possible. Make sure you hear a sharp click when you reinstall the oil drain hose, otherwise your bail connection is not secure.

There are other hoses connecting the CCV and they may also go bad over time, however, the lower oil drain hose seems to be the most common failure point. Additionally the CCV valve itself and the dipstick tube can also cause problems, however, these may be more to do with oil plugging the drain passages and cause oil leak and even possibly hydro lock the engine if things go really bad. More often in the much colder climates, however, the CCV is an issue all to itself and a search on the board here will offer many stories and solutions. One very good overall CCV thread is this one - https://forum.e46fanatics.com/showthread.php?t=870406

Pictures of a failed lower CCV oil drain/return hose are below. Note the thicker hose is the cold weather part number, this is what I would suggest installing. If you are in a bind, you can use 3/8" fuel line 10 3/8" in length but you may need to use spray silicon or heat the end of the hose to get it onto the CCV drain connector. It is a bit difficult to release the CCV hose connector in the blind, but if you notice it had an oval shape release collar, you pinch the wider part of the collar to make is circular and then it should release straight downward.

The parts numbers below are known to be for 325/330 engines, but again before you order parts for your car, please visit www.realoem.com and verify the proper part numbers for your application.


Lower CCV Cold Weather Oil Drain Hose, BMW Part Number - 11157532629

Complete ECS Tuning Cold Weather CCV kit (not you may want to also get the updated single wall dipstick and the larger, plastic air distribution manifold and 6 O-rings in addition to this kit?) - http://www.ecstuning.com/BMW-E46-325i-M54_2.5L/Engine/Emission/Oil_Separator/ES260026/

BMW M54 Engine Cold Weather CCV update part numbers

E46 (3 Series) rear-wheel drive only

Part Number Description Quantity
11 61 7 534 237 Oil Separator Repair kit 1
11 43 7 565 437 Dip Stick Guide Tube 1
11 15 7 532 629 Hose 1

E46 (3 Series) all-wheel drive only
Part Number Description Quantity
11 61 7 534 237 Oil Separator Repair kit 1
11 43 7 565 438 Dip Stick Guide Tube 1
11 15 7 532 629 Hose 1


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4. SAP (Secondary Air Pump) issues - First you need to make sure the SAP air pump actually runs. There are electrical controls, fuses, connectors that can contribute to a non working SAP air pump. Additionally the actual pump can fail as well, there are bearings that can and will go bad, causing a very noise pump and the bearings could possibly seize as well. I expect theh pump could also fail electrically, but for the most part I have seen/heard pumps with bad bearings that get extremely noisy. Noisy to the point that the pump can be heard 3-4 houses away when the car is started in the morning! So if you have any SAP specific codes, please make sure your SAP pump motor is working before you focus too much on hoses, valves and other items.

Rubber hose between the air pump output and the SAP air control valve, item #2 the following link for earlier cars - http://realoem.com/bmw/showparts.do?model=AR73&mospid=47730&btnr=11_2188&hg=11&fg=50. There appears to be AT LEAST 2 different part numbers depending on the model and year of car, BMW Part #11727555680 appears to use hose clamps on earlier cars, BMW Part # 11727555681 appears it may have quick connects used on later cars or 3.0L engines (330 cars)?? Check the part number of your application on www.realoem.com.
Might not cause stalling or a misfire, but can cause a CEL/MIL to light. These hoses start to break down due to the high heat from the exhaust transferring to the SAP air control value. They can cause problems with the SAP air control valve clogging or getting blocked.

SAP air control valve vacuum lines, items #3 & #4 in this link (Note - not all cars have a vacuum operated SAP air valve)- http://realoem.com/bmw/showparts.do?model=ET37&mospid=47720&btnr=11_2203&hg=11&fg=45 (both hard and soft line along the valve cover where the O2 sensor wires are routed) can leak vacuum and cause rough engine during cold start and possibly CEL as well. The SAP vacuum hoses, mainly the hard plastic pipe, crack due to heat over time and usually cannot be seen. Also the vacuum hose to the SAP air control valve usually do not pull vacuum except for the first 90 seconds on cold start so they often get missed when inspecting for leaking vacuum hoses. Note that not all engines have this SAP check value vacuum hose. I believe?? 3.0L engines/330 cars may not have this vacuum operated check valve (still trying to verify this)??? I believe if your air pump main output hose has the quick connect ends and not standard hose clamps, the SAP check valve is not vacuum controlled??

Also keep in mind there are a few other parts associated with this vacuum control circuit. There is the electric control solenoid valve, a vacuum check valve and a few other short vacuum hoses under the rear of the intake manifold and they are VERY hard to see and access, again, not all engines have this configuration. The electric check valve has been known to get debris in it from deteriorating vacuum lines and hoses. This debris can either block/clog the electric control solenoid valve or it may cause the debris to keep the electric valve from completely closing. If this electric valve gets partially stuck open I am not sure what symptoms will show up. The small plastic check valve and the few associated short vacuum lines can also be a problem. The issue is they are very hard to inspect and access. See picture of the underside of the intake manifold below a better view of what these items look like.

Simple test for the SAP air valve vacuum hose is to disconnect the small vacuum hose at the SAP air valve and connected a vacuum gauge to this connection and make sure there is vacuum applied for approximately 30 seconds or more on cold start up. The vacuum gauge should read approximately 15+ inches of vacuum. If you do not have a vacuum gauge, you should be able to use your finger to block the end of the hose to see of the hose is pulling vacuum on cold start up. If you do not get vacuum, then it is likely there is a problem with the vacuum hoses between the SAP air control valve and the connection under the rear of the intake manifold. Most likely cause is the hose and hardline from the SAP vacuum control solenoid under the intake around the rear of the valve cover and along the side of the valve cover near the O2 sensor wires.

The SAP vacuum control solenoid and a few additional shorts vacuum lines and a small check valve are all buried way underneath the rear of the intake manifold and are very hard to see and access. You really need a good light and a mirror. These short sections of vacuum hose and the small check valve can also be problems and you cannot easily tell if they are a problem, but I would probably replace the vacuum hose between the SAP air control valve and the SAP vacuum control solenoid first before I fought with the parts under the intake.

Note the vacuum line from the SAP vacuum control solenoid to the SAP air control valve only has vacuum applied for the first 30-120 seconds (typically around 90 seconds) on cold start up. So if you car runs fine from 90-120 seconds and beyond, I would think this is a likely source of your problem.Also keep in mind the SAP vacuum control solenoid vents to atmosphere when de-energized (engine off or SAP not running) , so you blow backwards from the SAP air control valve or use a smoke tester you will have leakage on the SAP vacuum control solenoid at the air vent, this is normal.

A few good SAP links to check over -

https://forum.e46fanatics.com/showpost.php?p=17161645&postcount=154

https://forum.e46fanatics.com/showthread.php?t=1041726

https://forum.e46fanatics.com/showthread.php?t=1023149

https://forum.e46fanatics.com/showthread.php?t=965526

https://forum.e46fanatics.com/showthread.php?t=1052605

https://forum.e46fanatics.com/showthread.php?t=1074847

https://forum.e46fanatics.com/showthread.php?t=1074573

https://forum.e46fanatics.com/showthread.php?t=106959

https://forum.e46fanatics.com/showthread.php?t=1074847

https://forum.e46fanatics.com/showthread.php?t=106959

https://forum.e46fanatics.com/showthread.php?t=1078986

https://forum.e46fanatics.com/showthread.php?t=1096889

https://forum.e46fanatics.com/showthread.php?t=1100895

https://forum.e46fanatics.com/showpost.php?p=17091432&postcount=28

https://forum.e46fanatics.com/showpost.php?p=17091517&postcount=29

http://www.bimmerfest.com/forums/showthread.php?t=430048&highlight=secondary+air+system

Late model MAF based SAP system info - https://forum.e46fanatics.com/showthread.php?t=965526&highlight=priceless

http://www.bimmerfest.com/forums/showthread.php?t=898977

https://forum.e46fanatics.com/showthread.php?t=809715

https://forum.e46fanatics.com/showthread.php?t=670441

https://forum.e46fanatics.com/showthread.php?t=921500

Page 6 of this BavAuto Fast Times Newsletter - https://www.bavauto.com/newsletter/2008_n408_newsletter.pdf

In the parts diagram below, item #3 which is the harder plastic vacuum line that runs along the valve cover gets extremely brittle and breaks easily, many times on the bottom where it is not visible. Many people just replace item #3 & both sort sections of item #4 with a single piece of vacuum hose from the SAP air valve to the extremely difficult connection to reach under the intake manifold. Also note there are a few additional short sections of rubber vacuum line that can also cause you problems under the intake, items #7 & #9.

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5. Basic vacuum hose leaks from caps, T's, fittings and hoses

Often overlooked at the 3 vacuum nipples located on the underside rear of the intake manifold. These 3 nipples can have a mix of vacuum hoses and/or vacuum caps plugging unused ports. The problem is the vacuum caps crack and can also fall off and cause misfiring and problems with cylinder #5 & #6. This area is hard to access and unless you know exactly what to look for with a mirror and strong flashlight, Smoke Testing may be the best way to verify leaks in this area of the engine.

Here are some useful links with pictures of what the underside of the intake manifold and some of the vacuum caps look like.

https://forum.e46fanatics.com/showthread.php?t=1074573&highlight=intake

https://forum.e46fanatics.com/showpost.php?p=17085769&postcount=36

https://forum.e46fanatics.com/showpost.php?p=17094253&postcount=2

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6. Check for coolant and oil ingress into the DME connectors. This is becoming a bit more common unfortunately.


https://forum.e46fanatics.com/showthread.php?t=1052977

http://www.bimmerfest.com/forums/showthread.php?p=9977321#post9977321

https://forum.e46fanatics.com/showthread.php?p=16833498&posted=1#post16833498

https://forum.e46fanatics.com/showthread.php?t=870338

7. Check the DME for coil driver chip damage. We are starting to see some of these show up as the cars age.

https://forum.e46fanatics.com/showthread.php?p=17093725&posted=1#post17093725

https://forum.e46fanatics.com/showthread.php?t=1114872

http://www.digikey.com/product-detail/en/infineon-technologies/IRGS14C40LPBF/IRGS14C40LPBF-ND/812253

8. Power brake booster and booster hoses leaking. We are starting to see these problems show up now that every E46 is 10+ years old.

https://forum.e46fanatics.com/showthread.php?t=1057387

Sucking Jet Pump Links

https://forum.e46fanatics.com/showthread.php?t=1061188

https://forum.e46fanatics.com/showthread.php?t=523763

http://www.bimmerfest.com/forums/showthread.php?t=578766

9. Smoke Testing is the way to quickly and easily find intake and crankcase air leaks.

https://www.youtube.com/watch?v=AsgB9eBl58I

https://youtu.be/1sRZ5ves1DM

https://www.youtube.com/watch?v=EhNQiIRsCCk&feature=youtu.be

https://forum.e46fanatics.com/showthread.php?t=1115860

Cheap fluid transfer pump from your local auto parts store or Amazon.

http://www.amazon.com/ABN-Multi-Use...=1-1-spons&keywords=fluid+transfer+pump&psc=1

A few rubber gloves, rubber bands and some cheap mini cigars from our local gas station or convenience store. You can also use a cheap E-cigarette and it may be safer than a lit cigar as well. Not sure if you can use mineral oil in the E-cigarette or if this would be to flammable.

Also get a good, bright LED flashlight to locate the escaping smoke. Look deep in the engine compartment and under the engine if needed. Do not forget the dipstick guide tube and the lower CCV oil return line. These areas may be hard to see from above in the engine compartment.

After looking for intake air leaks, remove the oil fill cap and allow the crankcase to fully fill up with smoke, then replace the oil fill cap. Check for cracks in the valve covers and leaks around the grommets, half moons and around the perimeter of the valve cover.

Common areas of leaks:

Upper and lower intake boots
Upper intake boot around F connector
DISA main O-ring and shaft area
Vacuum hoses under the rear of the intake
Fuel pressure vent hose that connects to the F connector on the upper intake boot and under the drivers floor board where it connects to the fuel pressure regulator
CCV and hoses, especially the lower oil return line
Dipstick and dipstick guide tube
Oil fill cap
Valve cover gaskets and cracked valve covers
SAP vacuum line to Kombi valve on front of engine, this will not leak smoke because of the control valve under the rear of the intake
Power brake booster sucking jet pump and hoses.

Note that the brake booster usually cannot be smoke tested because of the input vacuum check valve at the booster connection.

Other areas to look at include:
Intake manifold gasket, this can leak to single cylinder, cold start misfires that usually only happen after sitting overnight and at temps below 50F. These are almost impossible to test for with smoke and/or spraying with brake cleaner or carb cleaner.
CCV overall, but the oil drain back hose is the most common failure point.
Fuel Pressure Regulator vacuum hoses - https://forum.e46fanatics.com/showpost.php?p=14087261&postcount=30
Plastic check "T" fittings and associated rubber vacuum hoses and rubber caps - https://forum.e46fanatics.com/showthread.php?t=921500&highlight=
IAT (Intake Air Temperature) sensor O-ring leakage, O-ring is cheap and easy replace. BMW Part #13621743299 Note the IAT is located between intake runner #3 & #4 under the main engine cover.
ICV and its L shaped hose that connect near the throttle body.
Throttle body O-ring.
Upper intake flexible boot from MAF to coupler.
Power brake booster vacuum hose.
Air pump check valve vacuum hose.
Idle control valve and associated hoses.
Dip stick O-ring(s).
Fuel injector O-rings.
Oil fill cap.
Valve cover gaskets and small top seals.
Air distribution manifold and O-rings, over top of the intake manifold with a connection to each intake with an O-ring.
Fuel pressure regulator vacuum hoses.
EVAP hoses and valve.
VANOS seals, usually cause more MPG loss and upper RPM loss of performance, however, many have claimed that VANOS seals have help these issues.

Almost all of intake air leaks can cause misfire codes, O2 sensor codes, fuel trim codes, rough running and stalling. All these parts are basically rubber and after 7+ years and are starting to fail because they are subjected to high heat, gas and oil vapors, thermal cycling and vibration and it is time that they be replaced.

Lately there have been a lot of owners that have been dealing with what appears to be single cylinder, cold start misfires that cannot or do not appear to be corrected by eliminating vacuum leaks and they are being given advice to open the engine and replace lifters or take other drastic measures. There seems to be a lot of consensus that there is no way a vacuum leak can cause a single cylinder misfire. I say there clearly are certain vacuum leaks that will cause single cylinder misfires and it is my position that I would invest the time, money and effort to replacing hoses, seals and gaskets long before I would be taking the engine apart. You do have to use some logic on your approach and make decisions along the that that maybe you will pull injectors and have them professionally cleaned by someone like www.witchhunter.com before you possibly may pull your intake and/or tear into the motor. Also you may want to make sure you have performed a cylinder leakage and compression test long before removing the intake as well. Also do not forget to actually make sure the connector to the problem cylinder injector and ignition coil are tight, you may want to take a sharp pick and actually try to tighten the terminal inside the connectors for the injector and coil.

There has been some discussion that hydraulic lifter bleed down may be the cause of single cylinder, cold start misfires. This may be the case and a few owners have had lifters replaced, however, it is really hard to tell if the lifter was really the problem, or if when replacing the lifter a leaking valve cover gasket and/or other hose or gasket may have also been replaced during the repair that may have really been the source of the problem?? If it was my car, the LAST thing I would even consider would be to tear into the engine unless I had a really good idea that I had ruled out all the basic maintenance issues and common problems these car tend to have as they aged. Again, I would be focused on eliminating possible burnt valves early on in the process with cylinder leakage and compression testing, then methodically address the move obvious problems as I did things like professional injector cleaning and determining if intake manifold gaskets should be replaced.

10. Engine mechanical problems and restricted/clogged catalytic converters/exhaust

Something to also keep in mind, if you are totally unsuccessful in isolating a persistent misfire problem, please keep in mind you may in fact have an engine mechanical problem. Although rather rare, there have been a number of higher mileage cars that have been found to have a burnt exhaust valve in one cylinder. We have also been been seeing restricted and/or clogged catalytic converters also causing loss of engine power, performance and at times misfiring and even Lean codes. If this is the case the repair cost, required skill, time and effort is greatly increased. One problem is the sale of used catalytic converters tends to be against the law, so you will not likely be able to buy used exhaust manifolds with integrated catalytic converters from any junk yard/dismantlers. If you are lucky, you may be able to find a Forum member than has installed headers or has a parts car that may have a good used set of catalytic converters

When all else fails, do not forget to check the engine compression and perform a cylinder leakage test! I do not usually suggest these tests up front because the majority if these problems can be addressed with basic maintenance, however, as these engines get more and more miles added on to the odometer, we may need to change the philosophy about when to perform compression and cylinder leakage tests.

Following are some recently examples of burnt exhaust valve that caused persistent misfire problems both cold and hot along with some clogged catalytic converter threads:

https://forum.e46fanatics.com/showthread.php?t=889143&highlight=

https://forum.e46fanatics.com/showthread.php?t=904997&highlight=burned+valve

https://forum.e46fanatics.com/showthread.php?t=1124176

https://forum.e46fanatics.com/showthread.php?t=1123756


I had a car the other day with over 12 CEL/MIL trouble codes that included misfires on individual cylinders, misfires on multiple cylinders, O2 sensor out of range, O2 sensor codes, fuel trim codes.

Turns out the primary problem was the $11 CCV oil return hose between the CCV and the dip stick tube, also the DISA O-ring was rather loose. $25 later no CEL/MIL, no trouble codes, no misfires or rough running.

Quick suggestion, if you car is running poorly now that the weather is cold, replace at least the lower intake elbow, the DISA O-ring and the CCV lower oil return hose, clear the DME codes, about $50. Then worry about other things if the car is still running poorly or has additional CEL/MIL codes.

Other items that can cause problems and need to be kept in mind are (in not specific order): VANOS seals, MAF, Fuel Pump & Pressure Regulator, Coils & Coil Boots, Spark Plugs, O2 Sensors, Cam and Crank Sensors.

NOTE: Many times the Mass Air Flow sensor will soft fail or degrade over time and cause an under reported airflow amount, which in turn may cause the long term fuel trims to increase above the 10% mark. An indicator of a degraded or soft failed MAF may be that the short term fuel trim is within +/- 3% or less at idle, but your long term fuel trims are much further off. Additionally a degraded or soft failed MAF may cause the CEL to come on only on the highway and not around town. Vacuum/air leaks are more likely to trigger a CEL during idle and round town, where a degraded or soft fail MAF is more likely to trigger while on the highway.

Before proceeding with parts purchases, I have made every attempt to present accurate information here, however, it is your responsibility to verify part numbers @ www.realoem.com or other BMW parts guide to verify proper part application for your vehicle!

You can them use the BMW Part Number Price Comparison tool to find the best pricing on replacement parts - www.bmwpnpc.com This is a great tool written by a Fanatic right here on our forum.

Footnote/disclaimer on this thread, sorry if it seems some of my writing is a bit disjointed. This originally started out as a very simple 1-2 paragraph look what problem I had and how I resolved the issue. But then the thread this took on a life of it own. Many, many additions and edits and although I am not very proud of what I have put together, it will hopefully help some of you out with your problems. If I had enough time, I should really sit down and rewrite this information from the ground up so it is a bit more cohesive and clear, but I think overall most of you can see beyond my ramblings and will get the point. I do from time to time make corrections and additions as needed and as long as this thread has the edit feature still active, I may make slight corrections and additions from time to time. I hope this has helped some BMW owners out with identifying and correcting their issues and allow you to keep you car reliable.

Special thanks for the many other Fanatics that have allowed me to use some of their photos to illustrate this thread and help out the community! Also this information is a work in progress, if there are any mistakes, errors or omissions, please PM me with specific details, corrections and comments
 
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#92 · (Edited)
I believe on most engines it is located between intake runners #3 & #4 under the main engine cover, next to the valve cover?

But I realize you have a 1999 328 in your profile, I do not know that engine as well as the 325/330 series, so it may be in a slightly different location?
 
#94 ·
I have this link in my main post at the beginning of this thread. Altough expensive and a bit slow to ship, they are correct for the application from what I can tell. If you do you homework you can find many other sources, maybe not locally?
 
#97 ·
Curious on how many here have checked their ICV and how badly they are carboned/gummed up? Age and mileage might be a useful bit of info for others to judge at what mileage they get really bad.

Also for those that have removed and cleaned their ICV, did they also replace the rubber elbow/o-ring?

Lastly for anyone that had pulled the ICV, cleaned it and reinstalled, how much change did it make for the rough running/misfires, idle stability & stalling?

I can see where if the ICV is gummed up badly, it may not be able to control the cold idle well and it may also be slow to react to attempt to control the idle.
 
#99 ·
Curious on how many here have checked their ICV and how badly they are carboned/gummed up? Age and mileage might be a useful bit of info for others to judge at what mileage they get really bad.

Also for those that have removed and cleaned their ICV, did they also replace the rubber elbow/o-ring?

Lastly for anyone that had pulled the ICV, cleaned it and reinstalled, how much change did it make for the rough running/misfires, idle stability & stalling?

I can see where if the ICV is gummed up badly, it may not be able to control the cold idle well and it may also be slow to react to attempt to control the idle.
I'm thinking climate would be a factor also. Around here we get it all. Ice storms in winter and 110 degree summers with very high humidity. I would also imagine the type of roads would matter. Highways vs. round town driving. If you live in the country you would get more dust than city drivers. Especially if you don't change the air filter often. Wouldn't that dust be passed into the engine eventually??? There would be lots of variables I would imagine.
 
#98 ·
I now have 124k and mine still was decent, just lots of build up but still functioned correctly. I cleaned it and no change in idle.
Great post BTW, "excellent rating"
 
#100 ·
97k miles on my 2004 325Cic VERT .. the ICV was basically stuck. at first there was no movement when i shook it. took about a bottle of CARB cleaner to get it nice and loos where it would open and close when i jerked it. it did not however, take care of the problem. RPS still fluctuates and i get vibration when car is at idle. in my case the DISA is probably bad as well.
 
#102 ·
Car has 3 temp sensors.

One under the front bumper for outside temp, only used by HVAC and to display outside temp on OBC.

One for the Intake Air Temperature, located in the intake between runners #3 & #4.

One for the engine coolant temperature. This is what the DME uses for engine temp, the coolant temp gauge and Menu #7 on the OBC displays the coolant temp.

As far as I understand these coolant sensors do not fail often?
 
#103 ·
I did a quick check this morning of the SAP circuit vacuum switch to determine if it indeed vents to atmosphere when deenergized. And yes it does. After seeing a good 17-19 in. of vacuum during a cold start (and holding, implying no vacuum leaks) it did vent when the key was turned off (i.e. the vacuum went to 0 immediately). Hope this helps clarify the question. My issue still exists, bummer.
 
#112 ·
This was to help jfoj with the question of whether or not the vacuum line from the SAP vacuum switch to the SAP check valve vent to atmosphere. Since it does, blowing or sucking on that line will not help show vacuum leaks in the line. Just FYI. Thanks for all your input here jfoj!
 
#104 ·
I had the intake boot issue on my '01 and also my friends '05 and another '00 I worked on. When you get a lean code that is the 1st thing to check for! Usually right on the boot where it has the smaller hose end coming off it. I also had the vacuum lines dry rot on the air pump too. Good thread!
 
#107 ·
It is my understanding the sensor in the lower radiator hose is a electric cooling fan control sensor. Not sure if it is used by the DME for other purposes or not? On my E39 it has not impact on the coolant temp gauge or what shows up on the hidden OBC.

As for the ambient air temp probe, it is installed with the tip facing downward toward the passenger side tire. Many of the under panels get damaged and the probe socket can get damaged or broken out of the under panel. There is a probe socket that is connected to the passenger front under panel that the actual probe is inserted into.
 
#109 ·
It's possible that someone disconnected the ambient sensor and had it hanging down below the car and stuffed it in the holder backwards as you say?

The sensor stays snapped in the holder and you disconnect the wire connector when removing the lower panel, at least this is how my E39 is. The E39 shares a lot of things with the E46. Sometimes exactly, sometimes slightly different.
 
#111 ·
jmack,

Glad you made progress with your car and this info was helpful.

Overall some of what I list here is only a partial solution, but in the dead of Winter when the car is running badly, you want to get it drivable until the weather warms up. Then you can return to schedule more detailed repairs after parts have been ordered and you have found all of the DIY's for vacuum hoses, CCV and the like.
 
#113 ·
Kirk330i,

Thanks for confirming operation of the SAP control solenoid. I was looking into the exact operation of the solenoid and realized that there was an error in this part, I had made some notes in the main portion of the thread already about this issue.

How to easily check it is a bit tricky for a few reasons, temperature and time factor into how this circuit works. So you probably need either to put a finger over the end of the vacuum hose, use a vacuum gauge or maybe you can turn the ignition on when cold, without the engine running and hopefully the solenoid is energized, then you could either backwards on the vacuum line, you would need an extension as the hose is way too short to get your mouth on and/or use a vacuum pump to test the hose. The big problem I have is my E46 is a newer version without the vacuum controlled Air Pump Valve, so I have limited chances to get access to the correct version cars to confirm test procedures.

I will update beginning of the thread regarding this issue and see if I can find a concrete was to test this section of vacuum hose without getting under the intake, which is no fun on these cars!
 
#131 ·
Thanks again for all your input here jfoj, glad I could finally contribute something! I've been tracking my issue for a while now (shuddering around 2k rpm, mostly on decel), never throwing any codes, and running fine otherwise. I've been through everything I can reach (without the hands of a 10 year old!), replaced the entire CCV setup (kit from BavAuto), and still have the shudder. I'm really starting to lean towards a mechanical issue and not vacuum. I just replaced the AC tensioner assembly (nice, easy 30min job at night) as it was shot (could easily move it by hand in contrast to the new one) but still no joy. Is there a definitive way to check the motor mounts? One appears to have, what looks like, about a 1/2" wide shiny ring of oil around the top (drivers side of course). I'm assuming it could use replacement. I'm just leary of jacking up the engine by the pan. Seems like it could be asking for trouble. Anyway, off to think about it a llittle more, and bang my head against a wall. Thansk again jfoj, I know it takes a lot of time to post in as much info as you have. BTW, do you work as a BMW tech by trade? Cheers!
 
#115 ·
forzam,

Looks like the German Auto Solutions is offering the best options so far, decent pricing and I can bet they will be no worse about turn around time than the ebay person. Suggest you go with the silicon option, Viton is probably too hard and will not compress and relax enough. The ebay guy ships USPS and I think he is slow or sits on orders 3-5 days before he ships??

There was some confusion on the application between the different engines initially on my part and if you look at the German Auto Solution web link they want you to specify which engine you have. I think??? do not quote me on this, that there is a difference for the 323/328 vs the 325/330 set up?? I can't make heads or tails on the overall engine usage, maybe it is simple, but some of the info I have read, I would be hesitant to claim it is straight forward.
 
#117 ·
Updated the first post with additional info, removed ebay seller link now that there are some other options. Made some other corrections. Again, still a work in progress but hopefully it is helpful to the community.
 
#121 ·
ECS Tuning/BMW O-ring is for the M52 323/328 engines. This is the green O-ring many refer to. This is a serviceable part and there is no need to dig any silicon out of the DISA groove.

Ebay and German Auto Solutions referenced O-ring offers the smaller thickness 3/32" O-ring for the M54 325/330 engines.

Original part of the thread has been updated to reflect the differences.
 
#122 ·
I just ordered a DISA O-ring. thanks for the link/write-up.

Curious: Is it possible to have a vacuum leak and NOT have it throw a SES light? In other words, do vacuum leaks ALWAYS throw a light? I guess it boils down to how sensitive is the DME to a vacuum leak? Parameters..
 
#123 ·
To answer your question, not all vacuum leaks trigger CEL and throw codes. Some vacuum leaks may take a while before codes trigger, but if you have the ability to look at the fuel trims, this will be a good indicator some times.

But the problem with some of these vacuum leaks, usually O-ring and intake manifold gaskets, they sometimes really only leak and cause problems during colder temps where the silicon material is heat set and cannot expand back out to seal gaps when the engine cools off and all parts contract and shrink.

Usually hose failures can trigger CEL and lean codes, but again, usually the colder the temps the more obvious the problem.
 
#124 · (Edited)
I have the dreaded jerk/hesitation in 2nd & 3rd gear at 2000-3000rpms. Ive read just about every possible thread on the internet and there is no consensus on a fix. I need some help and fast or I'm going to do the unthinkable and sell the car.

The intensity of the problem varies from light to moderate hesitation...but is present every time I drive.

Most repeatable when lightly/moderately accelerating in 2nd gear thru 2000-2700rpms. Will repeat in 3rd gear at exactly 2100 rpm - 30mph. Seems to have trouble decelerating smoothly thru this RPM range. Driveline related....no issues with RPM range in Neutral. Car runs great from 3000RPM***8217;s to redline & highway driving above 40 mph

Problem seems fuel/air mixture or electrical or DME calibration/engine tuning related. I***8217;ve had a handful of times when the symptoms completely disappear- car drives wonderfully- then symptoms reappear within a day or two (approx. 20 miles of driving.) Problem has been present for over 2 years. No SES/CEL lights. Always use 93 octane fuel.

List of things I've tried so far:
- DME Update (Feb 2012)
- DISA Inspection & new O ring (Feb 2012)
- ICV Inspection & cleaning (Feb 2012)
- VANOS seals (March 2011)
- Spark Plugs (March 2011)
- Intake Boot (May 2011)
- Thermostat (May 2011)
- Ignition Coils (6) (July 2011)
- PreCat 02 Sensors (2) (August 2011)
- Fuel Filter (August 2011)
- Mass Airflow Sensor (October 2011)
- Voltage Regulator for alternator (November 2011)

Anyone with an idea?
 
#125 ·
I have the dreaded jerk/hesitation in 2nd & 3rd gear at 2000-3000rpms. Ive read just about every possible thread on the internet and there is no consensus on a fix. I need some help and fast or I'm going to do the unthinkable and sell the car.

The intensity of the problem varies from light to moderate hesitation...but is present every time I drive.

Most repeatable when lightly/moderately accelerating in 2nd gear thru 2000-2700rpms. Will repeat in 3rd gear at exactly 2100 rpm - 30mph. Seems to have trouble decelerating smoothly thru this RPM range. Driveline related....no issues with RPM range in Neutral. Car runs great from 3000RPM's to redline & highway driving above 40 mph

Problem seems fuel/air mixture or electrical or DME calibration/engine tuning related. I've had a handful of times when the symptoms completely disappear- car drives wonderfully- then symptoms reappear within a day or two (approx. 20 miles of driving.) Problem has been present for over 2 years. No SES/CEL lights. Always use 93 octane fuel.

List of things I've tried so far:
- DME Update (Feb 2012)
- DISA Inspection & new O ring (Feb 2012)
- ICV Inspection & cleaning (Feb 2012)
- VANOS seals (March 2011)
- Spark Plugs (March 2011)
- Intake Boot (May 2011)
- Thermostat (May 2011)
- Ignition Coils (6) (July 2011)
- PreCat 02 Sensors (2) (August 2011)
- Fuel Filter (August 2011)
- Mass Airflow Sensor (October 2011)
- Voltage Regulator for alternator (November 2011)

Anyone with an idea?
I have been noticing mine doing that so I decided to check fuel trims and a few other things, what I do notice is the car going rich when it does that.
With the condition I keep my car at I think it might be in the software inside the DME. Having talked to Jim C. some time ago it seems as though software straight from BMW isn't perfect.
 
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