Help! engine stall/rough idle problem!

[onewontdo]

I have 2002 325i with 78k miles. I bought it about three months ago, and only problem I had was some electrical (wiring) problems with my rear left tail light, and rough idling.

-Engine Stalling
Since a few weeks ago, my car has been stalling quite frequently. Whenever I am driving in city, (thankfully not in highway) the car "silently" stalls (no longer able to accelerate) as Service Engine Soon, Oil Warning and Battery Warning lights come on. And if I turn off and restart the engine, everything returns to normal and I am able to drive again.
This happened ever since the day that I attempted to push the car out of some ice patches. During my attempt to accelerate out of the icy ground, the very first stall occurred.

-Rough Idle
Whenever I stop the car while in 'D' shift, the car rumbles and vibrates (more on the passenger side) quite noticeably. And when I shift the gear to 'N', it no longer rumbles but the vibration is transferred from the seats to the steering wheel.
Also, I had noticed whenever I stop my car at 'D', the electronic MPG meter starts to drop rapidly.


Could these two symptoms be related somehow?
And what could be causing them?

I desperately need help, guys!
Drive safe.

[nathancarter]

The problem could be a number of things... first checks would be battery and alternator, next would maybe be camshaft position sensors, crankshaft position sensor, O2 sensors, maybe VANOS but that's more of a problem when it's cold.

As for the vibrations, my guess would be engine and/or transmission mounts. In addition to holding the engine/tranny in place, they absorb a lot of vibration. If they crap out, the vibration is transmitted to the car instead of absorbed by the mounts.

Is your Check Engine light constantly on, or only on when you have a problem? Check for any OBD codes, have 'em read for free at Autozone/Aamco/Pep Boys. If that doesn't turn up anything, maybe go for a "quick test" code read-out at a well-equipped independent BMW shop or maybe the dealership.

The auto parts stores will generally test your battery/alternator as well.

[Ion Donut]

+1 on the camshaft position sensors => rough idle & poor acceleration at low RPM

[skatetokil]

My car does the rough idling thing as well. It seems to be pretty random, but it will happen once a ride. Getting up to speed and stopping again, the vibration is gone. It it very intermittent, but it feels like the engine is trying to pull the car forward even though I'm totally stopped.

[BMWBurnout875]

all thos elights come on when yoru car stalls because your battery is still on so its not like those things ARE DEFENITLY causing the problem its just how it works just like if you turn your ignition on and not start the car so its not doing that because its just how the computer works...So yeah thats not causing the problem.

[skatetokil]

Is there a way to test the cam position sensor?

[skatetokil]

Also any way to determine whether the exhaust or intake is the culprit?

[CarthageHannial]

Also any way to determine whether the exhaust or intake is the culprit?

If defective the computer should throw a code. Different code for different sensor

As for the shaking; it's related to the same problem. The shaking occurs when the RPM needle goes down below the 500 mark; than it bumps it back up. Sometimes it doesn't and that's how it stalls.

I had an intake camshaft position sensor code and replaced it yesterday. The idle is much smoother and constant. I, however think that there's also something else involved in the mix. MAS could be a cause. But it's always safe to assume that the ICV might have a prominent role in this (since it deals with idle!!)

[e4wd4312]

Recently I replaced the Oil separator/Crankcase Ventilation Valve CCV w/ only 2 of the 4 hoses. and REMOVE AND CLEAN THE THROTTLE BODY. IT'S BEEN A MONTH AND A HALF AND NO MORE STALLING.... Check the site below. BTW I inspected all the old hoses and oil separator all of them seems to be good condition and no leak/crack.

[danewilson77]

I had a similar problem with idling and stalling. Especially when it was cold. Changed out the original plugs (104K on them) to mark sure I was getting a good spark, and then found a huge intake leak on the boot connected to my idle control valve. The way this corrugated boot is bent-the boot has a lot of stress on it. Cleaned the ICV with brake cleaner and replaced the boot. Idle and stall problems solved. I also had about six codes locked in that are now clear and have been clear since my repairs were completed. I started with the cheap things first and got lucky. The VANOS repair is very time consuming although not that expensive, so I opted to start with the small stuff. What codes are locked in on your car?

[VTHokieBMW]

The same thing happened to my sister's 2004 325CI last night. Her car however showed no signs before last night though. The temp was around 20 deg F when it happened last night and the car had been parked for about 24 hours. It also quickly got to the point after starting up, that the motor hydrocked! Its actually getting towed to my garage now. I hear it can be a pain to fix, but I'm going to attempt it to save her a little cash! Anybody that experienced the hydrolock have any advice? After reading other posts it looks like I'll have to replace the CCV, spark plugs, possibly the intake manifold gasket if it looks like it blew. Anybody have to replace the O2 sensors as well?

[DaveKennedy]

Our '04 325xi is doing the same thing. We've just had a new fuel filter, plugs, air filter replaced.

When the car shuts off the whole car goes dead and all the lights go off (dash lights) but the battery light was on. Dead/bad battery?

The mechanic did report an "O2" sensor code once but he said it wasn't consistent the next day there was no code when he restarted the car.