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Check Engine Light

11K views 146 replies 10 participants last post by  tomjohnson 
#1 ·
I recently had my check engine light come on and would like to locate the issue and get it back off.

What I've done so far is that I've taken it to AutoZone to read the codes. They told me that the codes are saying misfire on cylinders 1-6. I tried to do a little research on what would cause this and almost all of the info I've found so far points to the DISA valve.

I've removed mine and do not see any issues at all with it. It's not broken and is functioning fine with no play in it. I cleaned it anyhow and put it back but the light is still on.

What else might cause a misfire on all 6 cylinders? The car idles a little rough but not bad at all. I do notice that it is slightly a little more rough than before the light came on.
 
#2 ·
Ah, the forum crystal ball clinic is open. There are many variables to the code number and possible causes. Bravo for NOT changing 1 and 6 spark plugs as some would do. The code can be a result of a lean condition from a torn intake boot not visible to the eye. Feel, poke and carefully examine both rubber intake boots. A small rip can suck air making for weak mixture hitting the cylinders - misfire. Another favorite is a failing coil. Two at the same time would be unusual but who knows? Guys typically trade them around. As we have individual coils, swap #2 with #1 and #5 with #6. See if the mis-fire moves to #2 and #5 for example. If the symptom moves, replace the affected coil(s). While your in there toss in a fresh set of plugs if you don't know their replacement history. This rarely pays-off but eliminates coils and plugs.

Now it gets tricky. Deeper diagnostic tools or pro assistance may be required. Auto store OBDII code readers are fairly cheap. You can snag one with the error reset feature in the $45-$60 range. Don't worry about built-in code look-up data, we have the Internet for that. Having the reader in hand while troubleshooting is invaluable. Keeping your friends and neighbors from borrowing it is another matter. They never bring it back!!
 
#4 ·
Ah, the forum crystal ball clinic is open. There are many variables to the code number and possible causes. Bravo for NOT changing 1 and 6 spark plugs as some would do. The code can be a result of a lean condition from a torn intake boot not visible to the eye. Feel, poke and carefully examine both rubber intake boots. A small rip can suck air making for weak mixture hitting the cylinders - misfire.
The rubber intake boots may be an issue, for sure.

As far as the coils go, I would think that it would almost be an impossibility for coils 1 all the way through 6 to go bad at the same time. I really don't think it's the coils but then again, I'm not sure.

One thing that I do notice is that when the car is cold, it idles a little rougher than when it's warm and if I don't allow it to warm up for a while and immediately start driving, it will sputter. It's even stalled once or twice since this started. When it stalled, it was because I didn't let it warm up.

Does this still sound like an intake boot to you?

By the way, thank you, for helping me. :)

Auto store OBDII code readers are fairly cheap. You can snag one with the error reset feature in the $45-$60 range. Don't worry about built-in code look-up data, we have the Internet for that.
This is great to know and I will certainly pick one of these up tomorrow.
 
#3 ·
If your comment is that there's a misfire in cylinders 1 through 6, then there's likely a tear in your intake boot that's letting unmetered air into the system.

If your comment is misfire in cylinders 1 and 6, then there's likely an issue with the coils...but still check the intake boot for tears. And clean your MAF sensor. And your idle control valve.

Providing that you can feel the misfire, does the issue go away when you're off idle?
 
#5 ·
Hi Sam. Thanks for the reply. Actually, what they told me at AutoZone was that all the cylinders were misfiring. It's weird and I think as you and WhiteKnuckles have suggested, I will check the intake boots for any damage. This will probably be an easy fix if this is in fact the problem. I'll post back here tomorrow with my findings.

Thanks, Sam.
 
#7 ·
Hi Redbull, I'm not familiar with the pcv/oil separator. I looked it up and came up with like 4 or 5 different hoses on ebay.

Is the pcv/oil separator a collection of 4 or 5 hoses or just a single hose? Can you tell me if I should be singling out one particular hose?
 
#14 ·
I have a way of checking for vac leaks that has worked for me on 2 of my 325's, I take out the air filter box and MAF sensor,
Where the maf sensor attaches to that 3" rubber hose I stand to the side bend over and put my mouth to the 3" hose get a seal around my face and blow, you should be able to pressurize the system and listen for any leaks. if all is good you should be able to build up a pressure and hear no air leaks, I have found 2 bad vac lines to the fuel filter pressure regulator, torn intake boot, and cracked line to the valve cover.
You can hear the hissing right away if you have a problem, it helps if you have someone look and listen as you blow in and hold a slight pressure, It looks and sounds funny but it has worked great for me. no need for smoke testing.
 
#17 · (Edited)
This is really strange because I do not have a MAF because there is no "box", only a chrome pipe with a v shaped filter on the end of it. My car is a 2002 and I'm not sure if this is factory installed or an aftermarket thing. Does anyone know where the MAF is located in my case?

I'll take a pic and post it tomorrow when I can get into the garage.
 
#18 · (Edited)
You have an aftermarket intake... I'd honestly suggest that you swap the OEM one back in. You should be able to find the airbox for pretty cheap on either ebay or the classifieds on this forum (check the part out section).

Your car has to have a MAF, it won't run without it (well it will, but a SES light would trigger). It should be right behind the filter, it's the thing with a wire running to it.
 
#20 · (Edited)
P0300 - Random/Multiple Cylinder Misfire Detected
P1344 - Misfire During Start Cylinder 2
P1346 - Misfire During Start Cylinder 3
P1350 - Misfire During Start Cylinder 5
P1085 - Fuel Control Mixture Lean (Bank 2 Sensor 1)
P1083 - Fuel Control Mixture Lean (Bank 1 Sensor 1)
P0171 (B1) - System Too Lean (Bank 1)
P0174 (B2) - System Too Lean (Bank 2)
See above.

Your car is running lean. You either have a leak in your intake manifold, intake runner, bad MAF, have low fuel pressure, or insufficient fuel flow.

How old is your fuel pump and filter?
 
#22 ·
I had similer problems, I changed the spark plugs and coils Found 6 coils on ebay oem quality very happy with them.
I had changed the fuel filter 10,000 ago so I ruled that out.
I also changed the 2 O2 sensors up stream of the cats, cleaned the MAF sensor with the appropraite cleaner, New air filter, and a new fuel pump, (see diy here 20 minute job very easy) all codes gone runs awesome.
You can find alot of these on e-bay, I know alot say the stuff is junk but read the descriptions and warrenties and you can save some money, I ordered the O2 sensors from Advance Auto they are Bosch and saves 20% by ordering on line, had them in 2 days. You will need the O2 sensor socket to change them. I have had 4 BMW's in the past 8 years and never had problems with parts I have gotten on line, 2 I still have and the other 2 I sold to friends and are still running great.
Good luck
 
#24 ·
Thanks to all who have been following this thread and have offered help. I'm posting 4 images. You'll notice that the secondary air pump is broken away from its bracket and one of the hoses is slightly kinked. I'm not sure if this would have anything to do with any of the error codes I'm getting but I understand that this pump has its own code and is not in my grocery list.

Also, there is an image of my air filter, which is clearly aftermarket. I didn't install this as it came with the vehicle when I bought it. I removed the MAF and inspected it and it looks super clean; not even any dust inside. As per Sam's advice, I've inspected all of the hoses around the intake hoses as well as the intake hoses themselves and don't see anything cracked or broken. I will also try cleaning the idle control valve as well as doing other things that aren't that expensive. In the mean time, if anyone sees anything glaringly wrong in any of these images, please feel free to let me know.




 
#26 ·
Hi Sam, No, I didn't remove the intake hoses. What I did was a visual inspection and the large intake hose appears to be in really great shape. I will remove it though and inspect it further.

Is there a DIY for the removal of the intake hoses? I assume this is what you refer to when you say "intake", right?
 
#27 ·
codes are like dominoes lined up one after the other: as one is knocked down then the rest behind it also fall.
My point being be careful where u start at. You have to find the starting point (first code that triggered the rest)
I have had the same issue of misfire, wasnt maf, pcv, ccv or oil seperator....... has I have replaced all.
I recommend taking it in having it checked as all these recommendations can easily cost you a grand.
 
#28 · (Edited)
Woe, slow down guys! As johnnatalie posts above, we have collectively spent $1000 of the OP's cash giving him "good" ideas.

This would be an Internet diagnostic clinic (read: crystal ball). We need to work with fact isolation not best guess speculation.

Before throwing parts at her, start with what's known.The car is missing and spraying codes. The poster has not been clear with his skills, tools and troubleshooting experience. That's all we know.

I agree many of the suggested parts likely play into this and potentially need replacement anyway. A combination of problems can be challenging and frustrating to even an experienced mechanic. A professional diagnosis may be the best suggestion but we don't really know anything yet.

Pull a couple plugs and report the condition. But first, do you know how to read plugs? Are you familiar with aluminum heads and proper plug torquing? Do you have an OBDII code reader with reset? We have to start somewhere or we'll simply waist time speaking from our own abilities which doesn't help. I'm repeating Samdoe1's suggestions as he has good logic flowing but I disagree with the intake being a concern for the immediate problem. Get a plug read and report back.

We can visit the air pump later if no codes are present. You're solving for a misfire and/or fuel mixture. As another poster stated, your fuel trim maybe way off which is scary if it's detonating (pinging). Inspect all the intake rubber boots (hoses) from the MAF back. They hide under there feel and use a mirror. A clean MAF is good but doesn't mean it's not contaminated. That hair wire can have micro particles you can't see throwing off it's output. Don't assume anything at this point.
 
#29 ·
A combination of problems can be challenging and frustrating to even an experienced mechanic.
Yes, this is very frustrating. I'm contemplating selling it as I've only had the car a very short period of time and already have put over $1,000.00 into it and it still needs more money thrown at it.

Pull a couple plugs and report the condition. But first, do you know how to read plugs?
Do you mean spark plugs? Read spark plugs?


Are you familiar with aluminum heads and proper plug torquing?
No

Do you have an OBDII code reader with reset?
No

We have to start somewhere or we'll simply waist time speaking from our own abilities which doesn't help.
I agree with you. If you or someone can direct me, step by step, I'm happy to do what is asked of me. If you can tell me what to check first and what to look for, I can do that but honestly, I just don't know where to begin.

I disagree with the intake being a concern for the immediate problem. Get a plug read and report back.
What is a plug reader? Is this a OBDII code reader you are talking about? If it is, what brand do you recommend I get?

your fuel trim maybe way off which is scary if it's detonating (pinging).
What exactly does this mean? I'm sorry but it sounds like Greek to me. Would this be a bad thing?

Inspect all the intake rubber boots (hoses) from the MAF back. They hide under there feel and use a mirror. A clean MAF is good but doesn't mean it's not contaminated. That hair wire can have micro particles you can't see throwing off it's output. Don't assume anything at this point.
OK, I'll get back out there and inspect the hoses again and let you know what I find.

I am very familiar with working on vehicles. I'm not a mechanic by trade but I feel very comfortable working on my car. What is very frustrating to me is that even with these codes, the problem could really be anything under the sun. I am very, very limited on tools and cash right now so I'm sort of stuck between a rock and a hard place.
 
#30 · (Edited)
Excellent effort and honest reply. Now we have a baseline. I picked some of the terms purposely to see where we're at. To proceed, there's no guarantees. Your car may have a simple problem or indeed could be trouble a brewin'. Before you toss in the towel, Sam had you on the cheap and cheerful track. We'll get back to the OBDII reader and detonation later. Let's start with the easy stuff.

1st step: This is to see if the plugs are telling us more or if they're simply worn out.

After you complete the intake inspection, search "E46 Spark Plugs" on YouTube. Watch a couple vids on the procedure. Decide if it's something you feel comfortable trying. You are removing a couple plugs and inspecting (reading) the condition maybe after a cold start-up when she's kicking around? A plug "read" means examining them looking for indicators. You're judging the surface color, deposits, tip and electrode conditions. A lean condition is white in color. Rich has black fluffy deposits. Oil is wet where fuel fouled (also wet) smells gassy. This may help you what to report back. Google: "Spark plug reading". Lots of color guides and articles to help you.

Plug removal >>

http://www.youtube.com/watch?v=B_012eIMKf0

Plug reading >>
http://www.ngksparkplugs.com/tech_support/spark_plugs/faqs/faqread.asp
 
#33 · (Edited)
Excellent effort and honest reply. Now we have a baseline. I picked some of the terms purposely to see where we're at. To proceed, there's no guarantees. Your car may have a simple problem or indeed could be trouble a brewin'. Before you toss in the towel, Sam had you on the cheap and cheerful track. We'll get back to the OBDII reader and detonation later. Let's start with the easy stuff.
White Knuckles, thanks for the response. I'm going to replace the intake boots today and if the CEL doesn't go away, I'm going to do the plugs. I'm hoping that the boots will take care of this issue!

Thank you for posting the YT DIY on the plugs! It's very helpful!!
 
#31 ·
Yeah...throwing parts at a problem isn't something I would ever recommend but your situation seems to be fairly common with a fairly common set of parts that will have failed.

The cheap/free track I gave you should help you narrow down the issue pretty quick and WK is better than I am at explaining things. :)
 
#32 ·
Hey Sammy, thanks for following this thread and all your help!
Here is what I am going to do today. I called the dealer and verified that they have the intake boots in stock and they do. I ordered both top and bottom boots. They'll cost me about $50.00 for both but I think it's probably worth it to change them.

After I replace these, I'll post back and report the findings. Do I need to have the computer reset or will the CEL go off on its own?
 
#35 · (Edited)
If you purchased the boots that's fine as indeed they may fail soon anyway. Basically you're looking for an obvious rip discovered by poking, flexing and twisting. If you find a tear, that's good! Should the spark plugs appear white, it points to the same thing - lean. Sam ran your codes and as all cylinders were involved, we're thinking intake side. Your check engine light may not instantly go away so don't react after installing the boots. It may take a few cycles of operating the car to clear the conditions. We use the OBDII reader to speed that up. You reset and clear all codes. You then can see after servicing something, for example the boots, what code(s) come back and in what order.

We don't need the cool tools yet. We can pull a battery cable and attempt a hard reset if needed. Should your codes have greatly differed, meaning unrelated, Sam and I wouldn't offer false hope. Disappointment is to be avoided. Stay in there.

EDIT: I was distracted leaving the reply open. jmo69 had this above with the engine lamp. (reads like I'm repeating him)
 
#37 ·
You guys are great, thanks so much for sticking with me on this issue. OK, I've just returned from the dealer and have the boots in my possession. $55.00 for both of them. While I was talking to the parts guy, I picked his brain on some of the codes I've got. He went away and brought back a mechanic who told me while I have all the stuff off that I should also replace the one PCV hose that connects the PCV unit to the dipstick tube. So, I also bought that as well and will replace it when I replace the boots.

I also stopped off at AutoZone and bought a OBDII tool. While I was in the AutoZone parking lot, I read the codes and they are the same 11 that I mentioned earlier. What I did was I cleared the memory and drove it home which was about 10 miles. The dang SES light never came back on.

What gives? Should I replace the boots anyhow? Could there still be an issue that needs to be fixed?
 
#40 ·
Hey everyone, I've got some joy! Here is what I did.

I removed both intake hoses, DISA valve, the silver idle thingy and the MAF. I cleaned all these parts really well and then installed the new intake hoses. The top hose looked to be in perfect condition. It wasn't cracked or damaged at all. The bottom hose looked to be absolutely perfect as well. Since I had everything basically out, I could do a much closer inspection of the lower hose and at one point thought it was pointless to change it out because of how good it appeared to be. Then I noticed that the smaller hose that connects to the (manifold??) was broken. Bingo!! There was the issue (At least I was hoping). Now I started to get a little excited and couldn't wait to get the new hoses on the car and test it. I finished the installation and started the car, connected my ODBII unit and read the codes and saw 0171 and 0174. I cleared the memory, started the car a few more times and read the codes again and came back with a big fat, "0 codes". :clap:

A big thank you to everyone that helped me! Thanks a bunch guys! :thanks:
 
#43 ·
Yes, jmo, it certainly does feel great. The sun is shining and the flowers are in bloom. lol.

Actually, I've only got about $200.00 into the resolution of the CEL. Most of that cost was the OBDII reader that I had to buy to clear and read the codes. A very valuable tool at any rate. I've got over a grand in control arms, bushings and ball joints though. :(

White_Knuckles said:
Congratulations and welcome to "beat the man" club. That's right! Contestants research here and have an opportunity to cheat the dealer or shop. Avoid high service prices and get things done right the first time - by you.
Thank you White Knuckles! I'm glad to be part of that club and will give back to the community as often as I can. I really owe you guys a great deal of gratitude because the stealer wanted over $100.00 just to diagnose the issue and then who knows how much they would have charged me.

One thing I will say about this dealer here in Columbus, Ohio is that they were very nice and even directed me to talk to a service specialist who tried to decipher some of the codes and gave me some advice. Honestly though, the advice I get from this forum has been far superior.

I think I'm going to put this car up for sale and I'd like to get a 330Ci Coupe with a manual shift and sport package. That's what I'd really like to have if I am lucky enough to find one. :thumbup:
 
#51 ·
Yep. Less than 2 years old... I'll pull them out and check just to be sure. :D
I will report back. I'm also guessing I might have a bad O2 sensor or something going on... But my symptoms are the same as yours. This is why I asked. :) Thanks again! Will report back (hopefully with some evidence/pics!! :D)
 
#52 ·
The thing about codes is they can cascade from a common source. Never assume anything like there may be a bad pre-cat sensor. A torn boot can run the car excessively lean sucking air. The resulting air/gas mixture is crazy creating misfiring as well emission sensor errors.

Correcting one problem often clears the series.
 
#54 ·
I have to admit, when you told me this, White Knuckles, I was very skeptical but I have to reiterate what you are saying is absolutely right on the money. After I changed my intake boots, all of the other issues went away!

This is really good advice.

Now, I think I've found myself a new ride. :)

Can I get an opionin on this car? He's asking 4k with 200k miles on it. It's got the sport pkg and manual shift which is what I really want.

What would ya'll offer for this car?

http://columbus.craigslist.org/cto/3649019614.html
 
#60 ·
These cars can indeed be a problem in the 200K range like ANY high-mile car. If you don't want your yard to resemble Sanford and Son's think about your wish ride. Detail your XI, sell it and find a 100K, 330I with a manual and NO rust. That would be an $11000 car in my region but they show up in the $8-9K range sometimes. Used engines on the Left Coast run $2-3K and may include a scary history. Maybe things are different in the East but these parts fetch a premium.

Messing around swapping front end parts, engines etc. is dandy if you're a good wrench with lots-O-tools, time and a shop. These guys often win bringing back a car performing all the work. A basic owner needing shop services to do the needs often render themselves - upside down. The car is worth less than what's invested. You gotta really love the car for that one. Think hard and long Jedi.
 
#61 ·
These cars can indeed be a problem in the 200K range like ANY high-mile car.
The high mileage is honestly scaring me a bit. My Xi only has 140k on it and it's been acting up terribly.

Detail your XI, sell it and find a 100K, 330I with a manual and NO rust.
My ride is already spit shined and ready to sell. It's truly a looker; all stock but very nice. No rust what so ever and the body is very straight.

The issue I've been having with finding a car that I can be happy with is that there are not many manual shifts around in my price range. I thought if I could get 8k for mine, I could just reinvest that money in a manual shift. All of the cars I'm finding are over 10k.

Used engines on the Left Coast run $2-3K and may include a scary history. Maybe things are different in the East but these parts fetch a premium.
I just moved from California and I know what you mean about a cars history. "basketthis" said that a motor would run about a grand and was why I asked him where he'd buy one for that price. I'm also not familiar enough with the east coast to know what they go for.

Thanks for the advice White Knuckles. I'll think on this one before I do anything. One thing I'm certainly not set up to do right now is work on a car. No tools and no money generally means no ride. :(
 
#78 · (Edited)
This is great! Thanks! :D

Pre-cat O2, both front and rear. Buy from Amazon for ~$50 each.
This is what I've come up with to this point for information on the O2 sensors.
This is the expanded view of all the sensors.
These are all the sensor options from RockAuto.
A couple of questions.
First, I'm wondering if there is a test that I can do with my meter to test if the sensors are good/bad.
Second, obviously, which sensors are we talking about here? :hmm: They're listed as upstream or downstream. My guess would be upstream. But don't want to get the 100 dollar question wrong. :rofl:

EDIT: I wanted to include this link that includes the graph of my O2 sensors operating. Maybe this will help shed some light on whether they are good/bad, should be replaced/tested, etc??
 
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