95 318is idle problem when starting

[mario_m25]

Hi,

I have a 95 318is, 5spd and sometimes when I start the car the idle goes up then it goes down , this continues for few seconds and then idle becomes stable (in some cases the rpms go so much down that the car almost stalls). The problem occurs more often during hot weather or when the engine is warm. I have no problem with the idle once the engine runs, i.e. when I stop at the lights the idle is stable. I have checked the engine codes but nothing shows up. Any help would be greatly appreciated.

Thank You,

Mario

 

[johnnybmw1]

my car had the same problem a while ago... found out it was the oxygen sensor...
check with a local auto body shop...

 

[Big Daddy]

Auto Body Shop? Do you mean auto repair shop?

 

[johnnybmw1]

well some places do both

 

[mario_m25]

O2 senosr replaced

Thanks for the advice, I have cleaned the idle control valve and replaced the o2 sensor but problem still persists. I have noticed that when o2 sensor is disconnected it helps a lot. I have also checked the EVAP canister but it looks good, no cracks or anything. Could this erratic idle at startup be possibly caused by faulty knock sensor? From what I know replacing the knock sensor on M42 engine is a major job. I was looking on the internet for some write up on how to replace knock sensor but I did not find much.

Thank you for any help on this.

Mario