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BAD belt squeal problem, Solution?

2002 Blazer 4.3 with A/C 123,000 miles Automatic trans

Problem serpentine belt squeal that refuses to go away.

What has been done so far.

Replaced the Alternator with new factory part due to dry bearings and a bad regulator. Belt was chirping prior to this. Two different new belts, One Gates and one Dayco Replaced the upper idler with a spare. Different tensioner and pulley. AC compressor bearing is OK Water pump seems OK, no leakage and the bearings feel tight with no play. Power steering pump is also in good shape. With it running you can apply pressure to the tensioner with NO change in the squeal. Squeal goes away if you take tension off the belt so it stops. If you drip water on the BACK side of the belt with it running the squeal stops for a few seconds but comes back. If you drip water on the face of the belt there is no real change in the squeal.

Pulleys are in alignment and they are not worn to the point that the belt drops into the pulley and bottoms out.

What else is left?

In the AM I plan on pulling the fan and W/P and bench testing it then manually cleaning the belt path with solvent on the outside chance that something like a silicone got in there.

Reply to
Steve W.
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Is the spare upper idler new or used?

Reply to
Jarhead

New

Reply to
Steve W.

| > Is the spare upper idler new or used? | >

| | New | | -- | Steve W. | Near Cooperstown, New York

Okay- You said that water on the back side of the belt stops the squeal for awhile. What besides the idler contacts the back of the belt? It has been awhile but I think there was a fixed idler down low on my '93 S-10 with the 4.3

Reply to
Jarhead

On the 02 the upper idler and the water pump are the only items that run on the back of the belt. P/S, Alt., A/C, and tensioner are on the inside. It's a strange problem.

Been under the hood for a few years and this one just doesn't make sense. Figured I'd toss it out on the board and see if I'm just looking past the problem.

Reply to
Steve W.

Not familiar with a 2002, does it have a clutch fan or an electric fan? If it's a clutch fan, I'd start there.

Al

Reply to
Big Al

If going this route try talc power. You'd be sureprised. May be a combination of things though. Does it squeel after running for quite a while? (Long enought to charge the battery if something is draining it)

Reply to
Micah

Steve, another mech. trick: CAREFULLY let the back side of belt run across a file--preferably a round one, just enough to 'file' the glaze off the back side. WATCH your fingers!!! s

Reply to
sdlomi2

I would look again at the alignment, something is out of line, based on your description.

mike

Reply to
Mike Hunter

Sounds like a good plan. I had a similar problem with an '02 Exploder. After replacing the idlers and tensioner and the belt, I finally fixed it by cleaning the grooved pulleys with a tooth brush and brakeclean. Before that, I'd tried a bit of oil and then belt dressing. Both just made it worse after a minute or so.

Dave

Reply to
Hairy

Goodyear Gatorback belts are all I use now, keeps my Yuk quiet........

Reply to
Repairman

Reply to
Know one that you know

Well it turned out to be a couple things. The PS pump had a marginal bearing in it that was allowing the rotor to drag. Also found a bad bearing in the A/C clutch. It would only act up when it got HOT though. Couldn't find it when the bearing was cold, it spun fine. Pulled it down and replaced it. Belt squeal is now gone.

Steve W.

Oh and FYI if you need to pull the clutch on an HT6 compressor the PS pulley installer will also install the clutch hub.

Reply to
Steve W.

You think the water on the belt gave it enough grip to overcome the bad bearings?

Reply to
Jarhead

The bearing was running dry and as it got hot it was starting to bind up. It would still turn but REALLY stiff. The water was allowing some slip on the pulley.

Reply to
Steve W.

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