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Pulley Noise

383

By 383
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383 Enthusiast

383

Posted
Posted

My '01 Tahoe has a squeal whenever the engine is running. I replaced the belt and the tensioner pulley and it didn't help. I decided to start swaping parts with my '03 truck to see if I could pinpoint the noise. I swapped idler pulleys and alternators and the noise stayed with the Tahoe. I remover the AC belt and the noise is still there. The only other options are the water pump and the power steering pump, or am I missing something? Any ideas of what to try next?

Doug_Scott Senior Enthusiast

Doug_Scott

Posted
Posted

First thing you should have tried was to remove belts one by one until the noise went away to narrow down the source. Can you try that and see what happens?

383 Enthusiast

383

Posted
  • Author
Posted

There are only two belts, the serpintine belt that runs everything but the AC and the AC belt. I removed the AC belt and the noise was still there.

Doug_Scott Senior Enthusiast

Doug_Scott

Posted
Posted

So you have not tried removing the other belt? This sounds like you removed the one belt, still heard the noise and assumed it was the other belt doing it. Don't assume that. Remove all the belts, see if noise is gone. If it is not, then don't bother changing any of the belt driven items on the front of the engine. Noise maybe coming from in behind timing cover, could be the harmonic balancer, could be something else.

 

If the noise does go away, then put one belt on. check for noise, if it is back, then you need to look at what is one that belt, as well as the condition of the actual belt.

Do the same thing for the other belt if the first one did not make the noise. Does you truck have a clutch fan on it?

Use a long screw driver to check the belt driven parts by pressing the handle of screw driver into one ear, and touch the blade end of screwdriver on each of the parts. You will hear the noise amplify once you touch the part with the screw driver. Do not make more than one change at a time. You will end up following the wrong path.

383 Enthusiast

383

Posted
  • Author
Posted

Good thought! It sounds like a belt related noise, I never considered the possibility that it could be something else. Is it OK to run it for a short time without the belt?

gmtech4 Senior Enthusiast

gmtech4

Posted
Posted

My bet are the bearings in the alternator.

 

so long

j-ten-ner

he changed alternators already and same thing.

 

"I swapped idler pulleys and alternators and the noise stayed with the Tahoe."

j-ten-ner Senior Enthusiast

j-ten-ner

Posted
Posted

he changed alternators already and same thing.

 

"I swapped idler pulleys and alternators and the noise stayed with the Tahoe."

Sorry, my bad.

I promise to read more carefully.

 

:)

so long

j-ten-ner

Doug_Scott Senior Enthusiast

Doug_Scott

Posted
Posted

You can run the engine for a few minutes, I would not go past 5 minutes. The water pump is the one you have to mindful of. Does the noise happen all the time the engine is running? If it requires longer running, get it making the noise, then drop the belts.

 

You should also take a good look at the actual pulleys as well. Look for any damage to the grooves and also to the smooth pulleys as well for any marks on the surface that the belt runs on. You can also try spraying water on the belts with truck running and see if the noise changes. Don't spray any chemicals like wd40 on them. The stuff we used to apply to the old v-belts will damage serpentine belts.

 

Just so we are clear, you have tried NEW belts right? NEW does not mean different, it means NEW from store.

383 Enthusiast

383

Posted
  • Author
Posted

 

You can run the engine for a few minutes, I would not go past 5 minutes. The water pump is the one you have to mindful of. Does the noise happen all the time the engine is running? If it requires longer running, get it making the noise, then drop the belts.

Just so we are clear, you have tried NEW belts right? NEW does not mean different, it means NEW from store.

 

When the noise first started, I bought a new tensioner pulley and belt. There might have been a little less noise for a couple of weeks, but the noise came back. The noise is there right at start-up, it get's a little quieter after it warms up. I'll try it without the belt just to make sure, and also try spraying it with water. Thanks for your help.

txab Senior Enthusiast

txab

Posted
Posted

Also only replace the belts with Gates or Goodyear Gatorback belts. Don't use some the cheapshiz brands

383 Enthusiast

383

Posted
  • Author
Posted

Maybe that is my problem, the belt I bought is a Dayco.

txab Senior Enthusiast

txab

Posted
Posted

Dayco is usually not a cheapshiz belt. I put them in 3rd place behind Gates and Goodyear. Just not what I'd choose. Do as suggested and run for a short time with no belt first. you can get an auto stethoscope to help track down the noise. Put it to the water and power steering pump. It could be either one or even a fan clutch. You can take a piece of 1x2 about 3' long, place it to your ear and then place the other end against the suspected noise maker. The sound will be transmitted through the wood. Do this at your own risk. Watch for belts and pulleys......

Doug_Scott Senior Enthusiast

Doug_Scott

Posted
Posted

I have never had any luck with the 1x1 or 1x2 piece of wood. I found that the wood seemed to absorb the sound. I used softwood(pine once, basswood a couple of times), perhaps hard wood (oak or maple) would transmit the sound waves better. I have a long (24 inch) #2 Philips screw driver I used to aiming headlights. The handle fits better in the ear, and the shaft of the screw driver is about 1/4 inch in diameter. Gets into hard to get spots. Only bring this up to suggest he get the long screw driver before spending for an auto stethoscope.

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