I'm getting a strange grinding noise when driving my car (sounds like a piece of metal dragging on the street or somebody sharpening ice skates) but whenever I look to see what it is it seems to stop (almost like it's toying with me). It happens while at idle at a dead stop and even while driving at various speeds and disappears after awhile. I've looked underneath the car and nothing seems out of place or hanging. Anyone ever encounter such a noise or know the cause? Any advice would be appreciated.

 

is it coming from the engine bay ?

 

Could possibly be a bearing in any of the accessories under the hood such as alt, steering pump, water pump, idler, a/c compressor. If it is coming from under the hood, you could remove the serpentine belt and start it to see if the sound goes away. Don't let it run very long because the water pump will not be turning and it will overheat.

 

My guess is the A/C clutch...maybe. Turn on your A/C and see if it stops.