Engine Help

I’m getting frustrated….

2002 Silverado with the 5.3.

Been having an ongoing squealing under the hood. Thought it was a bad pulley. Replaced the idler and tensioner pulley. Didn’t help. Looking into it more, it wouldn’t squeal when the belt was off. I thought it was maybe a bad water pump bearing as it sounded off when I spun it. Replaced that and didn’t help. Now I’m just throwing parts at it.

In doing some further testing I found that the squealing stopped for a few seconds if I sprayed carb cleaner on the belt/pulleys.

There is some rust on my harmonic balancer where the belt hits but cleaned it with a wire brush.

Any thoughts?
DT

What does the belt itself look like? Really polished and shiny? That could be your squeal.

Looks to be in good shape. It is a little shiny but I also sprayed a belt dressing on it to try and stop the squeal.
DT

Try cycling the defroster on and off. Could be on the a/c compressor

Don Carlisle wrote:

Try cycling the defroster on and off. Could be on the a/c compressor

It does not squeal with the A/C compressor belt on or off.

Thanks
DT

DT belt dressing should never be used on a serpentine belt. Also serpentine belts don’t crack like they did in the past. You need to gauge how the ridge/groove is worn.
Is there a separate belt for the AC? If there is that belt needs to be very tight. It also would have a tensioner.

I would try a new serpentine belt. If its shiny it might be glazed over and be slipping

Good advice so far. If everything spins freely then you probably just need a belt. Try spraying it with silicone spray while the engine is running. Belt dressing is designed for old V belts and will more than likely make your squeak worse. Even a bit of coolant soaked into the belt will contaminate the rubber and cause slipping and squealing.

New belt.I would clean all the pulley’s and get the belt dressing off before installing new belt.

The tensioners in those especially the a/c were notorious for going bad. If you eliminate that possibility alternator would be next.

New belt X4

This is also why taking into a shop and having them tell you what you need is helpful. I know we guys like to handle stuff on our own. This is the exact case were that would have saved you money.

John Rasmussen wrote:

New belt X4

This is also why taking into a shop and having them tell you what you need is helpful. I know we guys like to handle stuff on our own. This is the exact case were that would have saved you money.

We will call this one “Preventative maintenance”….

Thanks for all the help. I will clean all the pulleys off and get a new belt.

DT

deertracker wrote:

We will call this one “Preventative maintenance”…

Didn’t mean anything by my comment DT, hope you did not take offence. Just I see a lot of guys come in with some new shinny parts and still having an issue. Only then to spend money with us to fix it. I have been there many times myself and tossed parts at a problem.

I also say stay away from that belt dressing stuff. I sprayed some on my truck years ago similar year I think to yours and it took out my alternator. I was apparently not very careful when I was spraying it though I thought I was.

John Rasmussen wrote:

<div class=”d4p-bbt-quote-title”>deertracker wrote:</div>
We will call this one “Preventative maintenance”…

Didn’t mean anything by my comment DT, hope you did not take offence. Just I see a lot of guys come in with some new shinny parts and still having an issue. Only then to spend money with us to fix it. I have been there many times myself and tossed parts at a problem.

No worries or offense taken. I get it. I’m usually pretty good with automotive fixes but this one kicked my butt.

My plan is to use a degreaser to get the belt dressing off and then soap and water to clean the degreaser off. Sound right?

DT

this is a pretty good video to diagnose a squeaky belt

deertracker wrote:

My plan is to use a degreaser to get the belt dressing off and then soap and water to clean the degreaser off. Sound right?

I would just clean the pulleys with some brake cleaner and call it good.

I recall having this exact issue with a 1997 C1500 Silverado, 5.0L vortec (my first truck).

I did everything under the sun before finally taking it to a mechanic with what little money I had while in college. Actually 2 mechanics… then 3. All were/ are trusted professionals, none ended up charging me a dime as they all separately concluded there is nothing wrong at all with the pulleys or the belt (I had purchased 2 brands of belt and also retained the original one for their inspection) and I should learn to live with it.

Squeal was noticeably worse on very humid or rainy days. A little baby powder on the belt would quiet it down for a week or so, but made a horrific mess of things under the hood.

What John said.Brake cleaner.

chuck100 wrote:

What John said.Brake cleaner.

Thanks guys. I won’t have time until Saturday but I’ll report back. Hopefully, about my squeak free truck.
DT

If not DT I’m in the north metro and would have one of my guys take a look at it, and make sure you get a proper deal. Good luck

That squeaking is annoying for sure. Dealt with it on multiple trucks.

Thanks John!
DT

Another thing that helps a noisy belt to help diagnose is Barkeepers Friend Cleaner. Put some on a rag and wipe down a couple areas of the belt WHILE THE ENGINE IS OFF! It comes in a liquid squeeze bottle. Don’t use the spray.

Used the Chris Fix video above to diagnose my son’s Corolla’s squeaky belt. Water made it go away with one squirt. New belt and tensioner and all is well. The tensioner pulley had a little wobble. It’s a 2005. I didn’t change it a few years ago because you need to jack up the engine to get the tensioner bolt out and didn’t want to deal with that then.

deertracker wrote:

<div class=”d4p-bbt-quote-title”>chuck100 wrote:</div>
What John said.Brake cleaner.

Thanks guys. I won’t have time until Saturday but I’ll report back. Hopefully, about my squeak free truck.
DT

Dont overlook a weak belt tensioner,, if origanal it could be weak and not holding proper tension

trumar wrote:

Dont overlook a weak belt tensioner,, if origanal it could be weak and not holding proper tension

Continuing from my post above:
My son’s car’s belt starting squeaking about 5 years ago. We would replace the belt every 12-15 months. As stated above looked into changing the tensioner but required lifting the engine on that side and didn’t want to deal with it. Found some you tube videos on replacing the tensioner and jacking up the engine and we did it in November. The tensioner pulley had a little wobble but the hydraulics were probably weak since it was 18 years in use.