Mysterious shaking after a warm restart - BMW F10 N55 535i

Question

I have a 535i F10, and I have the problem that the engine shakes itself strongly after a warm on and off (so that it sometimes even goes out). ISTA spits out P0172; which means that the DME either detects too little air or too much gasoline. Hasn't had a single engine problem in the past two years; really reliable.

About the symptoms:
Very noticeable jerking, stuttering and starting difficulties when the engine is warm.

The error only occurs after the engine has warmed up (approx. 20 min. highway trip) and ONLY when idling (symptoms become more severe after the warm engine is switched off immediately), so that it sometimes does not want to start at all .

What I did to remedy the problem

1. Intake manifold gaskets very carefully renewed. (Even if the fault cannot be on this component, since in the event of an air leak the DME would detect too much air and not too little (or am I wrong there?)

2. 6x new injectors, 6x spark plugs, 6x ignition coils, LMM, 2xLambdas, 2 suction pressure sensors, air and interior filters and engine oil changes with the Addinol, was quiet for the time being!

However, the car shakes again / still extremely after a warm switch off and on again.

Oh well, is it worth mentioning that I did a software update recently before the error occurred (approx. 2-3 days)?

I'm desperate

Answer 1

1. What update? Of what? So the error wasn't there before the update?

2. In the case of false air, you usually have the problem with a mixture that is too lean, meaning too much air and too little fuel.

3. Do you have any optimizations? Chip tuning, characteristic field or other changes?

4. You have suitable diagnostic software, just drive off with a cold engine, look at the live values! Then turn it off as you say and restart the warm engine and see what happens.

Answer 2

How high is your mileage?

Until recently I also had a similar problem, of which the ignition coils have made up a large part, but you have already exchanged them. For me, replacing the timing chain and both camshaft adjusters was able to fix the uneven running in operation. I also had no cold start fluctuations (137K km).

The Vanos solenoid valves can cause an idling jerk when cold, but you write that you only have problems at operating temperature.

Comments

108,440 km - I hope it's only because of the extreme short distance running.

My theory is:
Due to the extreme short-distance operation, the burned fuel does not evaporate properly, as a result unburned fuel (- vapors) remains in the combustion chamber. These get from the combustion chamber to the head and then back through the KGE to the intake system. Which makes it smell of gasoline in the head and the DME recognizes the mixture as too fat.

Does it make sense??

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No, an irregular run always has a cause. Idling in particular is a difficult state for the regulation, but mine was always inconspicuous.

If you hadn't replaced the injectors, I would have suspected another leaking injector.

Have you ever measured your compression?

I would also look at the spark plugs again, how they look after short drive.

Can you test the lambda probes via ISTA?