What could be causing a humming noise in my Pontiac Grans Prix?

Answer by  partsman (42)

Most humming noises can be traced to a bearing that's failing. Check your serpentine belt pulleys. Also, check the alternator bearing, located on the rear of the alternator. This bearing can be replaced, but you're better off replacing the whole alternator.

Answer by  spencerb (48)

If it's coming from the engine compartment it is likely to be a noise internal to the engine or either an accesory driven by the engine.

Answer by  scoyne88 (161)

It could be a fan or belt loose and rubbing against something. It could be shot bearings in the wheels, or it could be a leak in the exhaust system. I would check these things first, then start checking other systems by driving, turning air on and off, accelerating, decelerating and listen for the humming to change.

Answer by  DecalDude (36)

A humming noise can be caused by many different things. Most likely there is something loose on the vehicle. First you should look under the car and inspect the metal shields surrounding the exhaust system. Then you should check the engine compartment for any loose parts.

Answer by  frank52 (151)

If your Pontiac Grans Prix is making a humming noise you need to pull over to a safe area and check the tranmission fluid. The car needs to be running for a accurate reading. Most likely you need to chance the filter and the fluid.

Answer by  Chris22 (95)

Many things can make it hum. The fuel pump could be humming. If the hum comes from the rear of the car, like if it sounds like it's coming from the trunk, it is the fuel pump. If the hum comes from the engine, it could be the power steering.