I've researched this online, but have not found any specific inquiries via a Trans Am. I have a 2001 Trans AM WS6 , and everytime I'm stopped and the car is in drive and just idling and I turn on the air conditioner, the whole car starts to shake. But, if I put it in neutral or in park, and turn on the air conditioner, the shaking/rattling of the car stops. I have read that it could be a host of things, from ( Spark plug(s) being loose, the Spark plug cables, to the Tranny or motor mounts or even the IACV or it could be a leak in the Vaccum ). If any of you can narrow it down or help me pin point whats going on, I really appreciate it. Thanks alot - Mike

 

First item: Data log it, and see what comes up.

 

Clean your throttle body. Its not moving enough air to support the drag of the ac compressor.