20 codes and $3000 later....

I have never had more problems with a car in my life. My old plow truck is more reliable and it has 260000 miles on it.I was about ready to trade in my clk 320 and this 328i and get a newer 335xi, but I don't know about that now. Let me give you a brief history over the past year and a half. You can skip to the "current" paragraph if you don't want to hear me rant...just keep in mind I am REALLY stumped this time.

About a year and a half ago my exhaust cps went bad - no big deal, but, the first one didn't work (it was an aftermarket one) Convieniently and very difficult to diagnosis, during the installation of the second BMW brand cps, the fuel pump went bad - don't ask me how, that car was just sitting with the hood open. That was fun to figure out when it went bad while I was changing the CPS. So i did the fuel pump and the filter.

About a year ago I did the Vanos seals. Went pretty smooth, help the dipping idle problem. About six months ago the thermostatic fan stopped working. My wife was sitting at the gas station the car overheated and *bang*. We didn't know why it overheated until later when I found the fan was defective. The reservoir cap didn't relieve the pressure like it was supposed to so the pressure blew up the expansion tank, and cracked the plastic on the side of the radiator. So, I did the fan, thermostat, radiator core, water pump, upper and lower hoses, low water sensor, and car actually ran for about five minutes.

About 4 months ago - my wife was driving into Chicago to take her mother to the airport (about an hour away). I was on a job two hours from home (so she was three hours from me). She calls and says the battery light is on. I told her to pull off into a gas station. The car dies as I anticipated. I have to call and get it towed home - another $300 down the drain.

I replaced the alternator and during, find that the power steering fluid reservoir is leaking and looks like it was right above the alternator. Didn't see any fluid on the old alternator but could have contributed to the burn out. Replaced all the hose clamps around the reservoir.

About 3 months ago - check engine light is on, search the forums, looks like the MAF may be the problem, car will hardly run now. Intermitently looses power (extreme) and will die at stop lights if you aren't ready to keep the idle up with the accelerator when stopping. Hard to get the car going from a stop (again intermitently). Read that the cheap MAF sensors on ebay may be alright to use. DOn't know.

Currently - Replaced MAF and used a BMW CPS (intake side) because of the last codes I got read which was about two days ago. Car will still hardly run. Before the CPS change the codes were
P1250,
P0173,
P0170,
P0340 (why I changed the cam sensor),
P1188,
and P1189.

I am at a total loss. I am about to have a bonfire with the car as the fuel. If I unplug the MAF the car has more power and will actually run. Does that mean the the new (but cheap aftermarket) MAF is defective? I don't know what the most current codes are (specifically if the P0340 went away). I'm afraid to drive it to get the codes checked. I also forgot to mention that the serpentine belt squeals like crazy when I first start the car. It looks like the power steering pump is where the belt is smoking but the pump spins freely with the belt off, and the power steering works fine - but pretty sure that is unrelated to the CEL and all the other run problems.

HELP!!!

PLEASE.

You need to buy a code reader and actully READ the codes. Not guess what they can be.

As far as maf, yes a cheap aftermarket maf can malfunction. Search a junkyard for a used maf to further diagnose the problem.

I had a similar problem too. My car is 5sp and it would need serious revs to get it moving and would sometimes die if I put the clutch in. Turned out to be a vacuum leak.

goodluck.

sounds like you have a vacuum leak - it can trigger a bunch of codes - many of with are not related to anything other than the little leak - and buy a real maf - search around and you can get the PN for a hyundia maf that is exactly the same as the BMW (bosch) but the number is much cheaper.

Never buy a cheap after market MAF. I learned that from experience with my 325ci.

Have you checked your lower intake boot to see if it was cracked?

http://www.bimmertools.com/Peake-Res...r-BMW-s/51.htm

VDO-Siemens is the only "aftermarket" MAF you should be buying. It's actually the OEM for BMW's "genuine" MAFs.

CPS sensors and any other sensors should always be genuine BMW, but never aftermarket unless you know what the OEM is for it. Again, if you go with non-genuine BMW sensors, you may not get that 2 year unlimited mile warranty that you do with genuine BMW sensors. For the MAF, I went with VDO-Siemens...runs like a champ and is identical to the old genuine.

i think most of your frustration comes from using non genuine BMW parts. What has broken on your E46 is nothing unusual, but it seems that you are doing a lot of extra work from buying aftermarket parts then trying to diagnose the problems they create. eBay MAF's and aftermarket CPS's are notorious for causing problems.

I completely agree. This time, with the intake CPS, I went straight to the dealer and bought it for $120. I think I could have got it for around $100 online but didn't want to wait. I have seen before where cps malfunction could cause all the symptoms the car is exhibiting so I thought replacing it right away would solve my problems.

As for the MAF, I was stupid, and tried again to purchase on ebay. Already submitted a Return request and looking for the "hyundai" equivalant I read about on the forums.

Although, if one of the rubber boots between the MAF and the intake were cracked, couldn't it cause a MAF code as well? I would be surprised if I didn't have a crack in one of those boots. I plan on checking that out first thing in the morning.

OP, I too had many of those codes recently. My symptoms were loss of power, sluggish starts, engine misfiring, and stalling. I spent a little over $2K and randomly began replacing such items as fuel relay/filter/pump, DISA valve, Oil Seperator, intake boots, spark plugs, camshaft position sensor, and a few others. I got my codes read, and I had 15 different codes. I would do a few simple repairs if I were you to save some money and narrow down the possible culprit.

First thing I would do is pull the DISA and ICV and thorougly clean both items with carb cleaner. Make sure they are both free of carbon deposits and reinstall. Make sure you have no vac leaks, also make sure all electrical connections are tight and free of grime. I would get the current codes deleted, so that when the light comes back on, it will be easier to narrow down exactly which parts are failing. Have you checked the plugs to make sure they aren't fouled?

It could be those valves - I'll check for DIY, inspect and clean them. Are they hard to get at?

The vacuum leak is a good possibility but I need a DIY that show where and what to check. I'm not sure where all the vacuum lines go.

As for the plugs being fouled, I suppose it's possible but I don't think so because the car can run normal at times. The problem has been frequent be very intermitent and not even really consistant in the way it acts up.

You spent way to much money

Trade it in

I'd go with vacuum leak :/

car running better with the MAF unplugged - sounds like a vacuum leak to me

brosive05-
spent too much? what? the problems I fixed thus far all needed repair - obvious malfunctions.

Now I'm at the point where I don't want to spend money on unnecessary parts...that's the point of the post.

Pir4t -
I guess that's the general consensus here, vacuum leak it is.

I talked to an indy shop today and he said bring it by for a "smoke test". Any of you had vacuum problems that can give me some pointers before I begin?

I'm thinking like the others that it could be a vacuum leak and I would totally recommend buying the peake tool instead of a generic ODBII tool. Clear the codes with it, and then start checking the codes. It cost a little more than $100 but it has served me well. It dramatically drops the guess work out and has solved 2 or 3 problems for me easily already.

You need to get a Hyundai 2.5 VDO Siemens MAF and do a smoke test to find your vacuum leak. Living in the Chitown area, my money's on the CVV hoses being cracked and worn. Get a code reader as mentioned and stop throwing money into an 11 year old car. Good luck.

P0173,
P0170,
P1188,
and P1189.

Check one of your oil return hoses. I had those codes for past few months, mine had broken return hose(#2).
http://www.realoem.com/bmw/diagrams/h/e/54.png
After I replaced it, it pretty much cleared all the codes. Sometimes those fuel trim codes come back occasionally, but 1188 and 1189 are completely gone.

And p1250, it's a ghost code. I searched and found a solution, it's valve cover gasket.
It gives p1250 when there's a leak from valve cover gasket. Easy fix, cheap fix $50.

You've already replaced major parts that could affect engine's performance. Check for any leaks this time. Intake boots, old leaking gasket. They're usually cheap fix, but will take some time to fix.