540i cutting out

[kcld]

I have a 95 540i that 'cuts out' over 3000 RPM until the engine has been thoroughly warmed. It was even an issue when the weather was warm but now that winter has set in I need to drive for 15 minutes - well past the temperature guage registering normal - before the engine will rev past 3000. I believe I read somewhere that the engine management system will limit RPM's until the engine is warmed but this 'cut out' is on the verge of violent, it appears to be shutting down the ignition entirely until the RPM's drop below 3000. Since this usually occurs under moderate load it results in the whiplash effect! I had a crankshaft positioning sensor go out a few weeks ago and replaced it, but the bucking continues... Any suggestions on where I should look?

[ericcamaro]

I would try the plugs but it sounds a little more complex than that. I know that O2 sensors can act pretty weird until the engine is warm, my 525 would cut out until it was warm but was not violent but the o2 was just barely outa spec. start there and if you dont have any luck you may look at the MAF and see if it is in spec,

[Kalevera]

You probably need to reseal the intake. Pull the plastic ("acoustic") engine cover off and have a look down under it. Inspect for wetness/oil residue. Run a can of carb cleaner around the intake and at the junctions of the oil return pipe and see if the idle smooths out.

But, PCV plate + intake gaskets are known problems on the V8s. I did a 740 on Friday and an X5 was in earlier in the week for them.

The car will eventually become undriveable, may throw codes and the like.

Do a search, there's tons of info.

best, whit

[632 Regal]

do a reboot, then run the car. It should throw a code for you to read. Ill bet the plugs and boots are shot and swimming in oil in addition to possible bad coils. The intake leaks like Whit says are a common place but as far as I know they have more to do with low end/idle kind of engine codes.

[DaCan23]

You may have the problem I have and it's been looked at by 2 Indys and I've picked the brain of a stealer tech.... the best guess and a very uncommon problem, is that the Vibration Dampner/Reluctor Ring needs to be replaced.... supposedly... If you ever solve the problem let me know... I am planning on doing mine in the spring...

Other possible solutions, Crank Sensor... but you'll get crank faults from a bad reluctor.... O2 sensor or O2 relay.... PCV plate....

But I have done all those fixes and mine still has the problem...



I have a 95 540i that 'cuts out' over 3000 RPM until the engine has been thoroughly warmed. It was even an issue when the weather was warm but now that winter has set in I need to drive for 15 minutes - well past the temperature guage registering normal - before the engine will rev past 3000. I believe I read somewhere that the engine management system will limit RPM's until the engine is warmed but this 'cut out' is on the verge of violent, it appears to be shutting down the ignition entirely until the RPM's drop below 3000. Since this usually occurs under moderate load it results in the whiplash effect! I had a crankshaft positioning sensor go out a few weeks ago and replaced it, but the bucking continues... Any suggestions on where I should look?