top post....
12 pack of beer $10.00 pack of smokes $4.00 To honestly see someone stick a screwdriver in a engine with moving parts using their teeth. PRICELESS!!!!!!!!!!!!!!!!!!!!!
In all seriousness I don't use my "ear" I touch my teeth to the screw driver. They seem to transfer the sound better, especially the upper teeth. Use a long screwdriver stick one end to your ear, the other to the compressor. If the bearing is bad you will know for sure by the sound. If it isnt obvious look for the noise elswhere. If it is the bearing INSIDE the compressor it will make noise ONLY with the air ON. The pulley bearing will make noise all the time. It is very common for the pulley/clutch bearing to go out. It's about $25 at the parts store. You need the right tools to remove/install the clutch and pulley. If fact one of mine just broke so I ordered the kit from Harbor Freight today. ($25) It is a cheap one but good enough for home use. If you decide to do it yourself post back for detailed instructions.....Its not THAT hard to do.