When my car is cold I sometimes have erratic engine idling followed by Engine stall. If I identify this intermittent problem before it happens I can apply some revs and stop it happening. But this isn't a solution as I actually need my right foot to brake sometimes!
I have had this problem for abour 6 weeks now, it seems to happen at least once a fortnight and only before the engine us up to temperature. Today I realised that I can reproduce the problem on demand. When the engine is cold and idling, if I dab the accelerator and remove my foot instantly rather than smoothly it enters this failure state. The engine goes into a state where it sounds rough as hell and eventually dies.
Any ideas? There are no fault codes in the system!
It was definitely the cam sensor that was changed. That cured the problems I had previously.
Yep, it's the N42 Engine (Not sure about the B20A bit though?)
Yes, it's surprising I have no fault codes as when it dies it isn't pretty. The engine ends up in such a state the whole car is shaking! I would have thought a sensor somewhere would detect such unpleasantries!
Started the engine from cold and it was dying every time (I've developed a technique of killing it with the short sharp jabs on the throttle) Pulled the plug on the MAF Sensor and it didn't sound right but wouldn't stall. Plugged it back in and it was stalling again!
Does anyone know if it's an easy job to swap the MAF Sensor over?
I have a 2001 330i that has run once in 5 weeks. Every once in a while after I bought it in January (I live outside Detroit), the RPMs would bounce and it would shut off sometimes. Now it just won't stay on after it starts. The fuel pump/filter are both in good working order. Then I did some research about VANOS seals. I replaced them, and the car still stalls. I believe what happens is the faulty seals (look into these if you haven't already) cause other parts of the engine to break down more easily. They may just be the root of the problem. Does anyone have any suggestions for me? I'm thinking about replacing the intake camshaft position sensor. It could be so many things, but I'm really hoping that's what it is.
If changing the seals made no difference; then maybe widen the testing a little. How long does it run for after starting?
Have you read the fault-codes or had the live-data examined - something is changing between running and stopping. What's the fuel pressure like? Is the cyclone breather split and leaking air into the inlet?
It runs for as short a time as it can. If I step on the throttle, it'll stay on but really wants to shut off as soon as the rpms drop. There are no fault codes from an OBDII from autozone, but the Service Engine Soon light had been coming on and off for a couple months. As for any cracks, I have noticed none. When the car miraculously started a few weeks ago on a sunny day, I took it out for a drive and it was great. I'm definitely leaning towards camshaft sensor issues. It sounds like similar problems to what Aocal has been experiencing. If I unplug it and try to start, will this change anything?
Did you fix your problem? Mine is at the garage today for an Inspection II, he said while the car was in bits it's easier to check some other stuff, he mentioned air leaks. I'll update tomorrow if mine is fixed and if so what the problem was. I'm not to optimistic though.
It's been a while since you posted but in answer to your question, I have unplugged cam sensors, MAF sensor etc, this puts the default value into the ECU, if this fixes your problem then obviously the sensor you have unplugged at the time is to blame.
My car had the Inspection II at the BMW Specialists and they said that they did all the usual diagnostics but nothing came up (same as BMW had stated on the last 9 or 10 occasions).
However, since the service the problem has disappeared. So, an Inspection I didn't cure the problem, then the Oil Service didn't cure the problem but and Inspection II has removed the problem? So whoever knows what the difference is between an Inspection I & II holds the answer to the problem :-)
He did say my air filter was filthy, that's probably due to a lot of time spent on the motorway.
It was obviously something pretty basic, clogged fuel/air filter or dodgy spark plug or something. Shame BMW couldn't fix it over 12mths of hell. I've actually benefited from the BMW warranty running out and then going off to an independant. At least I haven't conked out pulling out on a lorry since.
Grrrrrr!! After a few months of pleasant motoring and begining to have my faith in BMW restored it has started happening again! Pulled out of work last night and had virtually no power.
It was really cold last night (Yeah I know it's August) it was 14 degs C.
Does anyone know of /recommend a DIY style 'plug in' I can get off E-Bay or somewhere that I can plug in, reproduce the fault, then analyse the data later to see why i've got no power at these intervals?
I've got an OBD II fault code reader but without a fault code that's a bit useless.
I drive a E46 318i and my car had similar problems - It stalled when cold and had no power until the engine temp came up to normal. I took it to BMW specialist and he replaced the thermostat which solved the problem on the stalling but the car still had no power when pulling away... They then removed the catalytic converter - which becomes blocked over time and increases pressure on the wrong side of the engine. This also didn't help much for the power loss and flat spots. The BMW specialist recommended replacing the Air Mass Meter to correct the problem - also no fault code because the meter hadn't failed completely. However, when I took the car to have the air mass meter replaced, by another mechanic, he discovered that a pipe, branching from the air hose after it has passed through the air mass meter housing has slipped off. Before we replaced the air mass meter, which is quiet expensive, he replaced the pipe and I took the car for a spin - it was fixed! The car had masses of power, so much so that the traction control came on when I powered through a corner!
So, I recommend that you inspect every air hose, as this is apparently a place where any weak spot (such as a loose pipe, tear etc.) can escalate into massive power loss and engine failure.
Thanks for your message. I wish i'd logged in earlier because I'm now going through the process of buying a new car. I've had almost 2 yrs of cutting out and the car has spent weeks in BMW dealerships and specialists but no one could fix it.
I'll have a look for loose pipes before I hand it over - just out of curiosity!
I have a similar rough idle problem on my 328ci (1999). Generally, immediately after starting it's ok and then after the cold-cycle completes - the revs drop rhythmically (almost dying) and it jumps back into life revving to about 1500 then settles - this repeats.
I also read the forums and decided to replace the VANOS seals. This hasn't fixed the problem. I was also considering next replacing the camshaft position sensor. When it's rough idling, unplugging the camshaft sensor does settle it down, but then I wonder whether the ECU just goes into a 'defaults' setting if and when any critical sensor is unplugged.