Replaced belt tensioner on 2002 5.3, squeal got worse SOLVED

[JohnnyRosso]

Hello. So, I have a 2002 Tahoe with a 5.3L V8 (241K miles) and I've been having some rough idle issues/ intermittent belt squeals for the last 50,000 miles or so. I've done a handful of things to calm the idle down, and I just replaced the belt tensioner pulley yesterday (the bearing was bad) in hopes my squeal would go away. When idling, the squeal is gone now. Oddly, whenever I hit the throttle now, the squeal is really bad (much higher pitched and louder than before) and sounds like it might burst. Not sure if I tightened the belt incorrectly and its too tight (or maybe too loose?)... Anyone have something like this happen before? I just want the belt to ride smoother. I'm going to try tightening and loosening it when I get a chance, but any advice is much appreciated. Thanks!

 

[MassHoe04]

Tensioners are spring loaded and apply the appropriate amount of tension on the belt automatically. If the belt is the correct size and not all glazed over, it must be another pulley seizing and causing the belt to squeal.

Take the belt off. Inspect for glazing.
If OK, look at the fan clutch and other pulleys to make sure they move the way they should.

 

[Fless]

Tensioners are spring loaded and apply the appropriate amount of tension on the belt automatically. If the belt is the correct size and not all glazed over, it must be another pulley seizing and causing the belt to squeal.

Take the belt off. Inspect for glazing.
If OK, look at the fan clutch and other pulleys to make sure they move the way they should.

^^ THIS. Also, do you know that it's not the A/C belt that's making the noise? Try removing that belt to help diagnose.

If you replaced just the tensioner pulley, do you know if the tensioner spring is good? Is the belt the correct one for the alternator size?

EDIT: tell us what mfr and part numbers you're using for the tensioner and the belt.

Looking from the top of your engine compartment, does your tensioner have marks (like below) and where do they land? Post up a pic of yours.

 

[MassHoe04]

^^ THIS. Also, do you know that it's not the A/C belt that's making the noise? Try removing that belt to help diagnose.

If you replaced just the tensioner pulley, do you know if the tensioner spring is good? Is the belt the correct one for the alternator size?

Looking from the top of your engine compartment, does your tensioner have marks (like below) and where do they land? Post up a pic of yours.

I'm still new to GM and the 5.3 and haven't taken a deep dive into the front end of the engine bay... I'm not used to seeing a completely separate belt just for A/C.
Good call on checking the belt, tensioner and A/C compressor pulley and clutch for noise!

 

[JohnnyRosso]

Ok, so I just checked out some of the other pulleys a little better and checked out everything you guys suggested. I don't have an AC belt.
1) The alignment on my tensioner is pictured- it is definitely off compared to you guys'. However, I can't adjust it any more without it loosening- could this be an internal spring or necessary tensioner replacement?
2) Also, I realized that another pulley is slightly loose and I want to replace it. I'm not sure what this one is called, but it is the bottom right pulley (I included a picture of my belt diagram). Do you guys know what that one is called?
3) I also am going to replace my idler pulley because the belt rides kind of on its edge for some reason, and I'm going to throw on a new belt even though mine isn't really glazed (as far as I can tell atleast) just for good measure.
4) I have a video of the current status but I'm not sure if the site will let me post it here. Have you guys uploaded a video before?

 

[Fless]

To post a video it needs to be hosted somewhere (like YouTube), then add the link in your message here.

The lower righthand pulley should be your power steering pump. And that tensioner looks like it's shot unless the belt is too long. What part number is your belt, and what alternator do you have (105A or 130A, maybe)? It should be stamped into the alternator body.

 

[MassHoe04]

Was the belt off one track on one of the grooved pulleys?

I had a misaligned belt once, when I had taken it off and put it back on for the fifth time on my wife's Hyundai. When winding the belt through, I did not get the belt onto one of the grooved pulleys completely. I was surprised it wasn't thrown off and shredded when I started the engine. Somehow, it managed to hang on until I noticed what was going on.

 

[JohnnyRosso]

To post a video it needs to be hosted somewhere (like YouTube), then add the link in your message here.

The lower righthand pulley should be your power steering pump. And that tensioner looks like it's shot unless the belt is too long. What part number is your belt, and what alternator do you have (105A or 130A, maybe)? It should be stamped into the alternator body.

Ok, so as far as I know I have a 130A alternator. I’m not sure what belt I have, but I’m going to get a new one and I will make sure it’s the right length for the 130a. I am pretty sure that my belt is the right size because it worked fine for the last several years until I started replacing things this last weekend. Either way though, I’m going to try and replace it with the idler pulley and the power steering pulley

 

[JohnnyRosso]

Was the belt off one track on one of the grooved pulleys?

I had a misaligned belt once, when I had taken it off and put it back on for the fifth time on my wife's Hyundai. When winding the belt through, I did not get the belt onto one of the grooved pulleys completely. I was surprised it wasn't thrown off and shredded when I started the engine. Somehow, it managed to hang on until I noticed what was going on.

Interesting! So, my belt isn’t off on any of the grooved pulleys, but it is off on the smooth idler pulley (which is so odd)- I wonder if it’s just slipping there?

 

[MassHoe04]

Interesting! So, my belt isn’t off on any of the grooved pulleys, but it is off on the smooth idler pulley (which is so odd)- I wonder if it’s just slipping there?

Grooved pulleys guide where the belt sits along the rest of the way. Kind of like a train on tracks. It goes where the tracks go. The fact that it looks odd on the idler pulley has me stumped. Is it the correct idler?

 

[DirtDigler]

I recently replaced tensioner pulley and had same issue with misalignment on idler pulley. Try flipping the idler pulley around, worked for me.

 

[DirtDigler]

Oops, flip tensioner pulley, not idler.

 

[JohnnyRosso]

Ok, so last night I was able to replace the belt and the idler pulley. The squeaking is gone! The idler pulley still rides a little off center, but it’s a smooth pulley with no grooves. It’s going good for now so I’m gonna keep checking on it and maybe add another spacer to line it up better

 

[MassHoe04]

Aftermarket pulleys often come with nothing else in the box, just the pulley.
Spacers or any washers would have had to been transferred over from the old pulley.

I have used Gates idler pulleys on other vehicles. Great product, but you have to use the bolt, spacer and any washers from the old part.

Here is what an AC Delco pulley looks like. New Delcos do include the whole thing.
There is a pretty good sized spacer you can see behind the bearing.

I'll bet an aftermarket pulley with no spacer was used and the original got tossed in the trash.

About $22 from RockAuto.

More Information for ACDELCO 36299

 

[JohnnyRosso]

So, the idler pulley I took off had a spacer just like the AC Delco, but it still rides on edge.

 

[JohnnyRosso]

Ok, so I've replaced the idler pulley and the belt and the squeal is gone! The idler pulley still runs a little on edge, and I think I'll add an additional spacer when I get a chance. Thanks so much for all your help guys!

 

[Joseph Garcia]

Ok, so I've replaced the idler pulley and the belt and the squeal is gone! The idler pulley still runs a little on edge, and I think I'll add an additional spacer when I get a chance. Thanks so much for all your help guys!

Thank you posting the solution to your issue. Much appreciated,

Our collective knowledge base has been increased.

If you could edit your post title to include the word 'SOLVED', it will help folks in the future who encounter a similar issue (to know that this thread actually has a posted solution).

 

[JohnnyRosso]

Ok, so quick update on this. When I first replaced idler pulley and belt in May, the squeal did go away. But, only a few days later, it started coming back.. but more intermittently. I got some other work done to fix my high idle (evap canister and O2 sensor actually helped a ton!) and then I wanted to figure out the squeal to get it running smooth all around. I realized the play in my idler pulley was actually because the part store sold me the WRONG ONE! So, I ordered the correct one (the AC Delco recommended on this page) and threw it on (much more stable, no play in idler pulley). However, now the squeal has gotten much, much worse. To the point where I don't even want to drive it around town, every time I hit the gas it screams bad. I keep checking everything on the belt and it is also totally normal, the same as before, just with new correct idler pulley. I'm wondering what could be causing this squeal? Is my belt possibly too tight..?

 

[NoReverseYukon]

I know I posted this before but,...

It sure diagnosed the misaligned power steering pump pulley on mine.
And this is what I used to adjust the pulley...

 

[rockola1971]

Ok, so quick update on this. When I first replaced idler pulley and belt in May, the squeal did go away. But, only a few days later, it started coming back.. but more intermittently. I got some other work done to fix my high idle (evap canister and O2 sensor actually helped a ton!) and then I wanted to figure out the squeal to get it running smooth all around. I realized the play in my idler pulley was actually because the part store sold me the WRONG ONE! So, I ordered the correct one (the AC Delco recommended on this page) and threw it on (much more stable, no play in idler pulley). However, now the squeal has gotten much, much worse. To the point where I don't even want to drive it around town, every time I hit the gas it screams bad. I keep checking everything on the belt and it is also totally normal, the same as before, just with new correct idler pulley. I'm wondering what could be causing this squeal? Is my belt possibly too tight..?

Your squeal might not be the belt. It could be coming from a bearing in the a/c compressor, alternator, power steering pump or water pump.