Guys,
I was dropping my daughter off for her first day of school several days ago & once I got back in my car the CEL came on & the car immediately starting running like sh!t. Like on 3 cylinders. I took it down to the local BMW & they did a diagnostic scan. The printout said :
Fault memory cylinder 1 has misfire detected 7 times,cylinder 2 has misfire detected 8 times,cylinder 3 has misfire detected 2 times,cylinder 6 has misfire detected 8 times. recommend further diagnosis of looking at coil & plugs.
The mechanic said it was most likely a bad coil pack or plugs.

So I ordered 6 coilpacks, 6 boot connectors & a set of new plugs. Installed all this today & their is no difference in the way it runs. It runs too bad to even drive.

My question is is would a clogged cat or fuelpump set off that many codes & make it run like sh!t.
Or what else could be the problem?

thanks for any suggestions/help

Curtis

man.. i would have told you up front to check further before buying the new coils, boots, and plugs. Yes, those components do fail, but they rarely fail all at once and together like that. Considering you have 4 misfiring cylinders out of 6, i would start by considering components that could affect that many cylinders at the same time.

the way i look at something like this is air+fuel+spark .. if you're absolutely sure you have ignition, and assuming air intake is fine (if it wasn't, you'd usually get some faults regarding unmetered air or MAF failure/out of range), then i would focus on fuel delivery. since you're all of sudden getting misfires on several cylinders, i don't think it would be the individual fuel injectors. i would look further upstream. simple way to start is to look for fuel leaks. then confirm with a fuel pressure test. is pressure too low? (maybe clogged fuel filter, fuel line leak, failing fuel pump) is pressure too high? (failed fuel pressure regulator?)

just some thoughts... but you need to start with a visual inspection followed by some diagnostic tests. speculation is only speculation until it can be confirmed. good luck!

thanks alot for the reply..Appreciate it.

It all makes sense. I should have known once they said misfiring on several cylinders. I know I don't have a fuel leak or I should be able to smell gas. I thought about the fuel filter....but the fuel pump usually don't go bad like that..or do they? I would figure it wouldn't start, let alone run if the pump was bad. Maybe it's going bad.


I'll do some diagnostic & visual checking once I get back into town next week.

Thanks again!!

bimmerZ5 (http://forums.bimmerforums.com/forum/member.php?u=20324) ,
You think it could be a dead 02 sensor causing my problems?
After reading the 02 sensor replacement article on pelican parts, it sounds like that maybe my problem. Symptoms:

Irregular idle during warm-up
Irregular idle with warm engine
Engine will not accelerate and backfires
Poor engine performance
Fuel consumption is high
Driving performance is weak
CO concentration at idle is too high or too low
Check Engine light is illuminated


I'm also going to change the fuel filter while I'm at it.

Thanks again!

An aged O2 sensor (useful life is 100k or less) will cause poor engine performance, but I've not seen of do so as dramatically as this. A fuel delivery problem, intake leak, bad CCV, or MAF problem is more likely to be the cause. Fuel pumps can suddenly fail and a check of pressure at the fuel rail will quickly tell if that is a possibility.

You think it could be a dead 02 sensor causing my problems?
...
I'm also going to change the fuel filter while I'm at it.
O2 failure is usually accompanied by CEL fault codes that indicate so. Something along the lines of O2 sensor adaptation exceeded.. yada yada. Also, O2 failure is a bit more gradual and less dramatic. Your problem seemed to come about dramatically, and my guess is something has failed catastrophically causing the several misfiring cylinders.

I do think you may want to go ahead with a fuel pressure test. And it is a good idea while you're at it to replace the filter, it's not too expensive and part of the process anyway. I'm not one to go crazy and change fuel filters too frequently, but maybe at least every 100-200K miles and since you're at it anyway.. makes sense.

Another thought came to me as well.... have you checked your coolant level recently? Is it low?

How do I do a fuel pressure check at the fuel rails? Is this something I can do I hope. I hate taking it to a dealer unless I absolutely have to.I'd rather do the work myself.Thanks again!
*edit*Coolant level is good. I replaced the radiator about 3 weeks ago due to the top flange breaking off inside the radiator hose. Also replaced the WP & tstat while I had it tore apart.BTW-car has 111k on it.

Checking the fuel pressure is simply a matter of attaching a gauge to the supply line to the injector rail.

Checking the fuel pressure is simply a matter of attaching a gauge to the supply line to the injector rail.
I'm going to put a new fuel filter on it tomorrow..With my luck, it probably won't fix the problem. I can't see that being the problem unless it's totally clogged up.
Anyhow, where can I buy a fuel pressure gauge? I would like to support the vendors that support bimmer forums.

You should be able to find a suitable gauge at most any autoparts house.

Well I got bad news :( I took it to a local dealer because a friend of mine is the sales manager there. After doing a compression test, they said there's no compression in cylinder 1 & very little in 3...the rest are normal.
I'm having it towed to a local bmw shop tomorrow to have it tore down & fixed.

What the hell could have caused this? Dropped a valve? Wouldn't be a blown headgasket would it? There's no water or anything in the oil.

I replaced the wp,t-stat,radiator not long ago...but it never overheated.

Should I have the chains & tensioners done why they have it apart?

This sucks :(

thanks

Oh man... that really sucks. Sorry to hear this... i was hoping that it would be something simple. I know how you feel though, one of my cars has a head gasket leak and it's bummed me out.

Do you know if the compression loss was for both wet and dry compression tests? if you plan to keep the car for a long time, while the motor is apart, i would have them do whatever is needed to make it last a long time.

Good luck man... take a deep breath... it'll get fixed and you'll be back in the driver's seat soon.

Well I got bad news :( I took it to a local dealer because a friend of mine is the sales manager there. After doing a compression test, they said there's no compression in cylinder 1 & very little in 3...the rest are normal.
I'm having it towed to a local bmw shop tomorrow to have it tore down & fixed.

What the hell could have caused this? Dropped a valve? Wouldn't be a blown headgasket would it? There's no water or anything in the oil.

I replaced the wp,t-stat,radiator not long ago...but it never overheated.

Should I have the chains & tensioners done why they have it apart?

This sucks :(

thanks