I too have a smog pump problem (calif. car). It makes chattering noises when the engine is cold, seems O.K. when warmed up (no noises). I'm still worried about it so I've disconnected the drive belt until I can get it fixed. How much time do I have driving around until it must be dealt with? The car actually seems to run stronger w/o the @$#%& smog correcting parisite. My thanks for your replys. -Jim380.

On almost all MB's the air pump is a WARM-UP device! Allows the O2 sensor & catalyst to heat up quicker, so the warm up emissions are lower! On your car it has nothing to do with any other emission control, only works w/cold engine.

Thanks M.B.DOC.