My car is making a squealing noise when I'm idling. When I'm driving on highway, I can't hear it but when I'm slowing down or idling I hear the squealing. It looks like it's coming from the belts. They feel pretty tight.

I went to my car to check the belt tensioner indicator and it looks a little wierd. I don't know what to make of it, so I'm attaching a file with a picture of what I see on the indicator. Let me know what you think.

 

Get a piece of heater hose and stick it in your ear (my favorite instruction to people!!) and probe around with the other end, to locate where the sound is coming from.

Could be an accessory, the water pump, tensioner, etc. Probably not the belt itself, but it's possible it could be (just not real likely).