E46 Idling problem during cold start...

[azizi.aziz]

Hi bmw drivers and zth forumer...

Right now...I'm facing this problem...BMW E46 Engine M54...only happen during cold start..the engine shaking (like running out 1 cylinder) can feel the car body shaking too...got fuel smell...and eventually the 'check engine' light ON...so I have switch OFF the engine...and re-start the engine back and everything running normal all day long even the engine have cooling down....but not till the next morning...

So every morning...I have to start my car twice ...It's abnormal isn't it...went to AB service centre...they detected cylinder#4 misfiring...but they don't know what to do next since the reading will return OK after restart the engine...

So need help from you guys...If happen you had this kind of experience...Thank you...

 

[chris_eunos]

do check the cold start valve since u said that the problem only happens during early morning.

 

[azizi.aziz]

thanks chris...emm which part is cold start valve???

 

[chris_eunos]

thats the problem, can ask a bmw mech to verify for you. Im no expert

 

[leonl]

On my E46 328i, it has an air pump on the right side (Driver side in MY) and there is a valve that recirculate exhaust gas when engine is cold to keep the emission down. My car used to have that problem in the morning, I replaced the valve and air pump (If you hear whining noise). Another issue you may have is the vanos seal, depending if your car is single or double vanos. You might have to replace the vanos seals, they are pron to go bad. Check this link. I think your problem is vanos seal related. Good luck.

Beisan Systems - Procedures - Double Vanos Procedure