mach1na

this has been going on for sometime and it would only happen occasionally so I never really thought too much of it.. but being as it has been cold recently, it seemed to be happening more often than usual and I discovered it only happens when I turn on my defrosters. After turning them on, there will be a strong vibration at idle but once I step on the gas it'll go away and come back once idle again.. happens for a short period of time but is this anything to be worried about?

owero01

Do you let it warm up a bit before driving? Give it a few minutes and then go. Are you using 87 gas? Try a tank of 93 and then go back to the 87. Maybe help blow out the carbon buildup.

nite

how many miles you got? it may be time to replace the serpentine belt or idler pulley.

mach1na

i've got around 50k.. and yes i let it warm up, i haven't ever really noticed it during cold starts, it usually happens later on when the car has been warmed up for sometime. and i actually run on 89.

jmk3

Check for clearance to exhaust hangers at midpipe, & heat shields. There is a new tsb that has to do with removing the hangers cause they cause noise in the center stack & shifter area. The hanger may touch the transmission crossmember & cause vibes at different times. Exhaust systems grow as they heat up.