Powertrain Mounts and Exhaust system

Shifting and abrupt throttle inputs cause the powertrain to move on its mounts. The exhaust system is attached to the engine and is hung by its own mounts from the body. The powertrain movement causes the exhaust system to sway on its mounts and contact the powertrain or body. With the vehicle on a hoist, the exhaust system can be pushed in each direction to see if there is a contact. Also look for signs of contact such as gouges in the metal or paint. The powertrain can also be moved on its mounts using a long lever arm such as a wood 2x4 to pry on various parts of the powertrain using the body as a fulcrum, again listen and watching for contacts. If greater than normal vibration is noticed at idle, the powertrain mounts may be failed causing the powertrain to move more than normal and to be out of design position to begin with.