Belt squealing, but only when under a load.
 

2001 Camaro w/ V6. Belt is nice and quiet until I accelerate or climb a hill... anything that requires over 2500rpm. Once the hill is climbed or the speed is constant, the engine quits working hard and the squeal goes away. It helps my mileage since I stay off the throttle as much as possible, but that was NOT to plan when I bought this car a few months ago! LOL

New belt, water pump, and tensioner arm/pulley. Any thoughts?

Thanks in advance!

SpeedRacer70

Re: Belt squealing, but only when under a load.
 

Did you install all those new parts in an attempt to solve an existing problem, or did the problem occur AFTER you installed?

Re: Belt squealing, but only when under a load.
 

The water pump seal blew out so I replaced the pump and decided to go ahead and replace the belt while I was at it. This is just before I started having this problem. In an attempt to remedy the squeal, I assumed that the belt just wasn't tight enough and the idler arm seemed to have a little slack in it anyway so I replaced the idler arm and pulley assembly. No change. After trying some belt dressing that also gave me no change , I tried another new belt in case the first new belt was just a little long allowing for slippage. ... still no change. (Both belts were standard belts from O'Reillys.)

Re: Belt squealing, but only when under a load.
 

Appears this happened only after the water pump was changed. Did the new pump have a new pulley, or did you swap it from your old pump?

I believe the movable part of the tensioner assembly has an indicator on it, that needs to be positioned within the limit marks on the body of the bracket. If the inidcator is not within the limits, the belt could be too loose. I suspect this is hard to see, but not sure, since I haven't really spent much time with the V6 engines.

Re: Belt squealing, but only when under a load.
 

The tensioner on a V-6 is not too difficult to see. Injuneer is right about the indicator. There should be a triangle and three marks. The first two marks are further apart than the 2nd and 3rd. The triangle should be between the 1st and 2nd (further apart) marks.

One other thing you should check is the alignment of all of the pulleys. When you bolted on the water pump pulley does it line up with all the other pulleys exactly when looking at it from the top? Same thing with the tensioner pulley. It could be a defect with the new water pump or tensioner that does not make them align.

When I had my V-6 there was a second idler pulley (the one by itself that does not tension it). I went through three of these as over time the pulley would pull itself off of the bearing it was pressed onto and would misalign with the other pulleys, something to check.

Re: Belt squealing, but only when under a load.
 

Announcer: "In our last episode of speed racer, we left our puzzled mechanic..."

Sorry guys... Had to do it! lol

Update: Pulled the belt off to confirm that I did indeed have a belt squeal that I am dealing with... the squeal, or whistle, is still there!!!

I backed the car down the drive and back up and when I revved the engine with no load or applied the brakes to create drag, I could still hear the high pitch noise.

My guess is that it is either the rubber insulator inside the harmonic balancer that is slipping, or a whistle in the driver's side exhaust somewhere. Going back to the chain of events in my mind, around the same time as replacing the water pump and belt, I also changed out my O2 sensors. The one on the driver's side was very difficult to get back in. Is it possible that I could have crossthreaded it and somehow left an airgap to create a whistle??? Has anyone ever heard of that happening? I know it is extremely unlikely, but I am to that point now.

What are your thoughts???

Thanks again guys for working through this with me!!!

-SpeedRacer70