Rattling noise

ZYANJAY1825

MEMBER
CHEVROLET S-10

I have a 1997 chevy s10 pickup 4 cyl. Just bought it second hand. There was a noise, like a whistling or screaming that we believed to be coming from the fan belt so my friend recommended using "belt dressing". After applying belt dressing the noise got louder so we applied more. Soon after the noise went away or so we thought. Noise came back but not as loud as before. In fact you can hardly hear anything. It does however present itself loudly when revving the engine. So many opinions on what could still be making that noise, but who to believe. Some say bearings need to be replaced, need tension on fan belt, crankshaft, timing belt, the fan itself, replace pulley. Please advise on what should be done. Thanks!

1 Reply

DPWD23

MECHANIC
136 POSTS

To narrow it down, take the fan off and run for a few minutes (don't forget to put the bolts back in or the pully will come off). If it goes away, your fan clutch is shot. Common problem that causes this noise. If it is still there, get a mechanics scope and listen at each accessory. You should be able to pinpoint where the noise is comming from. Don't forget to wear short sleeves, and be VERY cautious of moving parts when using the scope (of course while it's running).