Squealing from Under Hood on 2000 Silverado

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by daman4469, Oct 12, 2012.

  1. daman4469

    daman4469 New Member

    Hi all,

    Havent been on in a while! I have a 2000 Silverado LS 5.3L with 95,000 miles. I started her up yesterday after work, and as I let her warm up, a squeal began from under the hood. It wasnt a belt squeal, but more like a metal on metal squeal. It quickly went away, but came back again a few minutes later. The squeal grew louder with engine RPMs. I got it to squeal while it was parked, and I could tell it was not a belt, but could not pinpoint the source (too high pitched!) It is now becoming more and more common. My guess is a bad bearing on one of my tensioner or idler pulleys. I figured I'd get some opinons from others before I rip the serpentine belt off and start checking pulleys. The last thing I want is a pulley seizing and a belt breaking. Losing power steering/brakes and alternator while doing city driving is not good :) Thanks guys.
     
  2. PantheraUncia

    PantheraUncia Active Member 3 Years 1000 Posts

    My truck is a 2000 with the 5.3L (220,000 miles) and the only time I have had squealing was from a belt that needed replacing. Remember that there are 2 belts, the main one and the one for the air exchanger/compressor for the AC on the bottom left of the engine if you have the hood open and are looking at the engine by standing in front of the grill.

    I don't think the timing chain would "squeal" it would just break :). Does it sound more like it is coming from the transmission than the engine? is it in park at idle, or when driving? is it at low rpm or high rpm or both? It might be the power steering? does it happen when you turn the steering wheel? and is the power steering fluid at the correct level, when was it changed?
     
  3. daman4469

    daman4469 New Member

    I didnt have my AC running at the time, so I doubt its the clutch, although it could be those bearings as well. This sound is more of a screech than a squeal....it sounds more like power steering than a belt. Its coming from the front of the engine for sure, but its hard to pinpoint since its so high pitched. Park or drive, it does not matter. It fluctuates with engine speed and RPM. I can not seem to get it to 'only happen when i do this, or only when i do that'. Its coming and going as it pleases but is coming more than it is going. Power steering level is OK.
     
  4. Conlan Rose

    Conlan Rose Rockstar 3 Years 1000 Posts

    Its the belt. I can almost guarantee it's the belt, happened in my 96' couldn't find the squealing thought it was everything but the belt, got a new one and boom like magic no noise, but remember its recommended to replace idler pulley and tensioner, especially if they are factory because they wear over time as well.
     
  5. Pikey

    Pikey Moderator Staff Member 3 Years ROTM Winner 1000 Posts

    I would just take the 5 minutes and pull the belt off. Then spin the pullys by hand and see if any of them feel or sound crunchy.
     
  6. Conlan Rose

    Conlan Rose Rockstar 3 Years 1000 Posts

    Adding to [MENTION=51590]Pikey[/MENTION]'s point, all pulleys should spin without much effort except for the pulley from the crankshaft.
     
    Last edited: Oct 12, 2012
  7. craigandi

    craigandi New Member

    Just for the hell of it -turn your ac on next time it's squeeling....
     
  8. j cat

    j cat Rockstar 4 Years 1000 Posts

    the tensioner must keep the belt tension constant. if worn/binding it will cause the belt to make noises.

    replacing the belt if with cracks is required.

    the pulley bearings with the belt removed will reveal the bad bearing.

    with this type problem it must be checked out before replacing parts.
     
  9. WorthFlorida

    WorthFlorida Member 2 Years 100 Posts

    While the engine is running and you hear the squealing, spray a little WD40 on the grove and the back side of the belt. If the squeal goes away, then it is the belt, if not? Keep looking.
     
  10. Hidef

    Hidef New Member

    On my old 2000 I had to replace the A/C belt tensioner after it went bad and I also had to replace the alternator after it started squealing. You need to pull the belts and check every pulley a bad bearing will squeal. If you haven't change the belts in while it is a good time to do it.
     

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