mercedesc240 shakes

[sd77chawla]

when i get to stop sign or stop light it shakes bad not all the time but it does 1 out of 3 times. it loose rpm to 250 or less and regain itself back to normal like 600 or 700 what should i do

[jwhughes3]

I would suggest your indy take a look at the motor mounts - cars shaking at idle almost always point to a deteriorated motor mount.

Now why does the engine RPM dip below normal and then come back up? One reason I can think of os the transmission not coming out of lock-up (this normally occurs when you are coasting down off load) and the engine gets lugged down and then the tranny unlocks the torque convertor and RPMs return to normal.

Without looking/driving your car I am only guessing, but these are 2 things I would check out. It might just have a sticky throttle plate and only need some Gumout carb cleaner squirted down the intake to clean things up.

John in San Antonio