Have a question for anyone that may be able to help ...have an '02 cls auto trans. that when in drive and stopped at a light on the brake and waiting will almost stall out. Idle is normal and will drop about 500-600 rpm in a pulsing manner. This only happens after car has sat for half the day and is totally cold. Dealer has not been able to recreate the problem and i'm getting more aggravated! Computer, sensors, etc...maybe??? Anyone?? 40K, always serviced w no other issues.

 

What about the plugs and air filter?

 

When you say "pulsing" do you mean the rpms are fluctuating, like someone was stepping on the gas and then letting off?

If so, it's more than likely the idle air control valve (IACV). Search the board for IACV and find out how to clean it or just replace it.

 

What he said

 

yes exactly but only when in drive if that would make a diff? If i flip to neutral even with brake still applied it's all good. It lasts for about the initial 5-10 minutes of drive regardless when i warm the motor...