I just purchased a 2000 GXE with 82,000 miles.

When I reverse, the car viberates but when I press on the brakes hard the vibration stops. It feels like it's from one or both of the back brakes. Also it's not constant sometimes it doesn't vibrate but it usually does.

When I took the car for a NYS Safety Inspection the service station said the brakes were almost new.

Does anybody have any ideas on what it can be.

Thanks

 

check the hose that leads to the brake booster. perhaps the clamp broke or it is just barely sitting on and making the engine surge when you are in reverse. does it do it in any forward gears (not sure if you are 5spd or auto) at the same rpm as in reverse? if there is not enough vacuum then it could cause the motor to stumble and idle horribly.

 

It only does it in reverse (auto) when the car is moving and only when I am not stepping on the brake. The engine is not surging.

 

sounds like it might transmission related. when you apply the brakes, does the vibration go away immediately or just when the vehicle stops?

 

It stops right away.

 

Does anybody have an idea????????????????????

 

I think you need to change the rotors.