I have a new noise in my engine compartment. I will describe it as a grating sound, that rises and falls with RPM. It sounds a bit like a worn bushing or bearing, but also has a rattling sound . The water pump was replaced 40,000miles ago; the alternator 15, 000 miles ago; timing chain 30,000 miles ago. All systems are go: charging, cooling, oil pressure - all are normal. Is the fan clutch possibly the source of this noise? BTW, engine mileage is 232,000.

 

Fan clutch, power steering tensioner, a/c compressor / idler.

maybe try a piece of hose (like a stethoscope) in one ear and move the other around listening for the source of the noise.

 

v-belt idler pulley bearing? i had one go bad and thought it was the PS pump. it wasn't making noise though, only causing the belt to squeel

 

The easiest way to check is to start taking off belts.

First, the PS belt. Then the Alt belt. Then, the AC belt assuming you have AC. That will eliminate all accessories, and the only thing spinning would be the crankshaft pulley. If its still making the noise, you have a problem inside the engine. If not, you have an accessory problem. Taking the belts off one at a time will tell you which system it is (PS, Alt, or AC)

 

Thanks for the replies. I will follow up on your suggestions this weekend.

 

Turn on the A/C and see if it changes. That will eliminate the compressor and you don't have to wait till the weekend.