After a high speed run , I hear high pitch sound intermitently or whining like two metals grinding each other. I hear this after I stop with engine running on park. It is hard to determine where it is coming from.. idler pulley, alternator or ac compressor. Tried screw driver test( motorvate )...sticking the screw driver to the 3, pulley , alt, and AC and the handle to your ear to hear the sound difference among the 3. Didn't find much difference.Alternator is functioning well or else end up with a dead battery by now. Any body had experience this before? Any suggestions?. I am tempted to just change the idler pulley from junkyard. I hope it is not the alt.... TIA

 

Im having a similar sounding problem. I get a nasty whinning noise out of no where and it eventually goes away. Even when I turn the car off and remove the key from the ignition the sound persists. Any ideas??

 

Tighten the belts...

 

And when that doesn't work, buy new belts and rough all the wheel with emery paper before installing the new ones.

Dave

 

It could be the alt if you hear whining. Do you smell burning wires under the hood? It could be the alt.

 

Why wouldnt it? My belts got loose over the winter and would squeal like piggies, I just had to retighten them. Unless your belts are losing ribs, its fine. Most people hear the high pitched squealing and think its something else.

 

It doesn't take much squealing for loose belts to glaze and for the pullies to lose grip. Retightening only works for me if I catch it immediately after its starts making noise.

Dave