E46 325Ci (M54B25) shutting off engine while driving

[mpc007]

Yesterday I drove home after work and got stuck in traffic on the motorway. Then this strange thing happens, where the engine would just shut down when I engage the clutch pedal (its the manual 5 speed) and the revs fall back. It's almost like the rpms fall back too much, as to a state where it can not recover and just shuts down. After that, I tried pulling up full gas to see if there were other symptoms, and it appeared some power was missing, it was clearly not accelerating as quickly as it used too. Still, it could hear no odd sounds from the engine bay (I mean, when its limping on less than 6 cylinders it can be heard quite clearly) and I had no error lights on the dash.

I had a similar issue on my old Peugeot 106, and I never found out what it was due to there being multiple reasons why it could happen. Still, its quite annoying and even dangerous when the engine shuts off regularly in traffic or at the red light when engaging the clutch pedal so I really want to solve this issue before doing any other work on the car (i have quite some projects with it on the side). The car has no other serious issues, it's using some oil (~1L per 1500kms) but not too much for its 192000 miles and this particular engine.

Internet tells me so many different things, that I am really looking for some advice on what the most likely causes are for this particular car. The E46 with gasoline 6-cylinder is not uncommon, so my bet is there are some drivers here who will have a clue

Thanks in advance!

Edited by mpc007 on Thursday 15th November 23:14