Thread: Loud rattling noise coming from belt area

I just replaced my coupler and mine is doing the rattling noise to

Yeah my S/C coupler is new, and as I said, the rattle still occurs with the supercharger taken out of the picture by virtue of its belt being off

well if you find anything out let me know and ill do the same.

Originally Posted by jpearsall187

I had the alternator run on a tester at Advance Auto. It didn't make any noise whatsoever. I guess that leaves me with the A/C compressor. Is there a way to distinguish between a problem with the air gap between the clutch hub assembly and the clutch rotor and a problem with a bearing?

Sure. If the air gap is too small, it will make a light metal scraping sound when the AC is off. And you should be able to replicate it when turning it by hand. And you will probably see metal shavings clinging to the compressor clutch.

If the bearing is bad, it will feel gritty when you turn it by hand. And/or wobble.

had this problem last week its your harmonic balancer. cheap part its also called your idler pulley if your getting noise its loose tighten it and if its broke they only cost 50$ its located infront of ur water pump

Ok, so I finally got back to looking into this problem after I broke off a power steering bolt in the engine block and was dealing with that. Anyways, I adjusted the air gap on the A/C compressor and that did not stop the loud rattling I get at idle. So here is the latest: the car has a very loud rattling at idle, which disappears with just a small increase in RPM. Turning on the A/C at idle decreases the noise somewhat. I removed the supercharger belt: the noise DOES NOT go away. I removed the main drive belt and there is still somewhat of a rattle, although it is not as loud or as continuous. Could this be the crankshaft pulley/harmonic balancer assembly? I noticed when I had the engine dropped down that the rubber in the center of the the crank pulley was starting to deteriorate. Thanks everyone

Any chance this is a timing chain/timing chain tensioner problem? I really hope not

as i said

Originally Posted by kyleinkman

had this problem last week its your harmonic balancer. cheap part its also called your idler pulley if your getting noise its loose tighten it and if its broke they only cost 50$ its located infront of ur water pump

OK, thanks, ordered a new harmonic balancer in case it is not loose. Will look at it tomorrow

Anything like that? Mine made that noise and ended up being the water pump.

i kno im right haha

OK, so I replaced the harmonic balancer and the rattling sound is now gone. However, I now have a squealing/chirping/whining sound coming from the belt area. It didn't do it before I put the new balancer on. The sound gets louder as the RPMs increase, and after the car runs for 10 to 15 minutes, it seems to almost go away. Any suggestions? It does seem to go away somewhat also when I spray WD40 around the power steering pump pulley (which is new). Just seems weird.

Also check the tensioner pulley. If you can, spray it while the car is running and its chirping and see if it goes away. My 95 Bonneville does this and it's the pulley. Dobbs thought it was the belt as well even after I told them it was the pulley ( I know because I hit it w/ spray lithium grease and it stopped for a bit) and they replaced the belt. Guess what, about 1 week later the noise came back.

I would double-check the alignment of the pulleys to make sure you got the HB fully seated on the crankshaft. Maybe it's out of alignment so the belt is being forced to flex.

So I put another belt I had layin around on it (the belt is used) and now it doesn't chirp/squeal at idle but it squeals/chirps when I rev it/the car is under power and the sound doesn't go away after it warms up like it did with the belt that was on there.

The belt tensioner assembly is new. And it wasn't squeaking until after I put the new harmonic balancer on. This may sound basic, but what is it about bad belts that make them squeal? Also, there is a small coolant leak around my water pump. I believe it is the gasket, as it seems to be leaking out near the back of the pump over the power steering pump. The weep hole is under the pulley right, so I should get coolant on the belts and all around the engine bay if it was coming out of that right? (Just want to make sure my noise is not coming from the water pump, although I had the pump off a couple of weeks ago and all seemed ok).