I own a 98 cavalier and for the longest time when my car has sat over night or is parked on an incline nose down it will make a pop/thump noise when after I put it in reverse and hit the gas to move the car. It almost seems like the torque in the engine is causing something to bang against one another.


I just can't find it! I have had people under my car while I go through the motions of trying to get that noise to appear but for some reason it will only do it once and a while.


What could it possibly be? Strut mounts? Motor mounts? Something else entirely?

 

Sounds like bad motor mounts except for the fact that it has to sit over night. Have someone brake torque the car while you watch the engine. Likely it will be flopping around.

To brake torque, have your assistant start the vehicle, apply the parking brake, hold the brake pedal with their left foot, put the vehicle in drive and proceed to blip the throttle. Repeat these steps with the car in reverse.