2006 5.3 L33 Problems..belt Squeel

Buddy67Lincoln · March 2, 2008

I have a 2006 Sierra with the L33 aluminum block 5.3. I bought the truck with 8,000 miles after it sat for 6 months. Soon after the belt squeels real bad. I listed and it sounds like alt. bearing when I took the belt off and turned the alt and haeard that squeel. I took it in...the belts bad. Got a new belt. 1,000 miles later, they put conditioner on it after it starts up again. 1,000 miles later, more noise...more "conditioner." This time I am pissed off. I tell them to not put conditioner on it and fix the problem. Conditioner is a cover up; its temporary. They gave me a "one time good faith belt replacement" from the shop manager. They found the belt gunked up with something so it needed replaced. I said, its probably the magic conditioner you have been putting on it. I had to have a can under the back seat since I went from Pittsbrugh to Philly with miles totaling 850 miles and it squeeled 130 miles into the trip! I put the belt conditioner on it and it only worked till I hit the highway. They said it was me and that the dirt is getting in there. "Its all open in the front of the engine so it gets dirty and dried out"...Its been doing this since the summer, not just the winter.

IS IT ME? or does every L33 do this? I know my neighbors 04 does not make noise. I have the duel electric fans so the front it more open, but why design something like that if this is a common problem? I think its something else, but do know what. Thanks for any help and sorry so long. Needed to get the story out so you know where I am comin from.

VMax2007 · March 2, 2008

Pulleys are probably mis-aligned.

Buddy67Lincoln · March 2, 2008

Pulleys are probably mis-aligned.

oooh noooo, they checked all that. The 3rd time they said they pulled it all apart and checked...conditioner! Once it happens again, I am taking it to the Chevy dealer down the street instead of the GMC dealer (different company).

Buddy67Lincoln · March 2, 2008

Pulleys are probably mis-aligned.

oooh noooo, they checked all that. The 3rd time they said they pulled it all apart and checked...conditioner! Once it happens again, I am taking it to the Chevy dealer down the street instead of the GMC dealer (different company).

Sorry if I sound sarcastic or pissed off...I am, but this problem is getting rediculous. If there is any mechanics who have seen this problem, please let me know if this is normal procedure. I would think you would want to figure the problem out and not keep putting condition on the belt or just keep replacing the belt. I might have to try another GM garage for my warranty work. Thanks for any help in advance.

pm26 · March 2, 2008

Belts tend to squeal when they are not tight enough because the driven accessories, like an alternator have some resistance to turning, especially when loaded. The squealing is caused by the belt sliding over the pulleys. Tightening a regular V belt is easy, if it is a serpentine belt like the one on your truck, it is automatically tensioned with a tensioner with a built-in spring. It is quite possible that you have a defective tensioner with a weak spring. Tell them to replace the tensioner and go from there.

And I would definitely not use any dressing on the belt.

Another thing that can cause a properly tensioned belt to squeal is a malfunctioning alternator. Not the alternator bearing, but rather the voltage regulator going open putting out higher than normal range voltage. I had this happen to my military truck. It has a 24 Volt system, and the alternator belts started making this awful squealing noise when I started the engine. The alternator has two V belts driving it. I tensioned both again, but no improvement, still squealing. Then I put a voltmeter on the battery terminals (two 12V batteries connected in series) with the engine running and I saw almost 31 Volts! Should be about 27-28 Volts for that system. Turns out that the alternator voltage regulator went south, it was charging wide open, putting so much load on the alternator that two properly tensioned V belt were sliding through the drive pulleys. Replacing the alternator immediately solved the problem.

This may not be your problem. But I want to point out what I experienced. Have the alternator and the charging system tested too.

VMax2007 · March 2, 2008

Pulleys are probably mis-aligned.

oooh noooo, they checked all that. The 3rd time they said they pulled it all apart and checked...conditioner! Once it happens again, I am taking it to the Chevy dealer down the street instead of the GMC dealer (different company).

I have heard others say they had their pulley alignment checked and were told they were fine, only to find out later on they were not. Evidently, even the most MINOR misalignment can cause this. I have heard it's typically the PS pulley that is the culprit. Have another shop check your pulley alignment again.

Buddy67Lincoln · March 2, 2008

Pulleys are probably mis-aligned.

oooh noooo, they checked all that. The 3rd time they said they pulled it all apart and checked...conditioner! Once it happens again, I am taking it to the Chevy dealer down the street instead of the GMC dealer (different company).

I have heard others say they had their pulley alignment checked and were told they were fine, only to find out later on they were not. Evidently, even the most MINOR misalignment can cause this. I have heard it's typically the PS pulley that is the culprit. Have another shop check your pulley alignment again.

Thanks a lot. I will have them check it ASAP. By the way, your truck looks great. I was afraid to get a V MAX since gas prices suck, but I am only getting about 12.6-13.5 in town. The highway pays off though, I can get 19.3. But I know those V MAX engines must move! My 5.3 moves pretty good as it is.

Buddy67Lincoln · March 2, 2008

Belts tend to squeal when they are not tight enough because the driven accessories, like an alternator have some resistance to turning, especially when loaded. The squealing is caused by the belt sliding over the pulleys. Tightening a regular V belt is easy, if it is a serpentine belt like the one on your truck, it is automatically tensioned with a tensioner with a built-in spring. It is quite possible that you have a defective tensioner with a weak spring. Tell them to replace the tensioner and go from there.

And I would definitely not use any dressing on the belt.

Another thing that can cause a properly tensioned belt to squeal is a malfunctioning alternator. Not the alternator bearing, but rather the voltage regulator going open putting out higher than normal range voltage. I had this happen to my military truck. It has a 24 Volt system, and the alternator belts started making this awful squealing noise when I started the engine. The alternator has two V belts driving it. I tensioned both again, but no improvement, still squealing. Then I put a voltmeter on the battery terminals (two 12V batteries connected in series) with the engine running and I saw almost 31 Volts! Should be about 27-28 Volts for that system. Turns out that the alternator voltage regulator went south, it was charging wide open, putting so much load on the alternator that two properly tensioned V belt were sliding through the drive pulleys. Replacing the alternator immediately solved the problem.

This may not be your problem. But I want to point out what I experienced. Have the alternator and the charging system tested too.

Sorry I missed your post before. Thanks a lot. I will have them check that out too and get the system tested. The only thing I notice is that my volatage jumps up and down while on the highway. I look at it and over 14 and other times is lower, but never in the red of course. I have to look closer to know exactly what it is when it drops. Could this be a sign? If I am not mistaken, it even jumps over 14, but I know 14V is normal, right? Thanks a lot.

Mikeee · March 2, 2008

I've always used the Goodyear Gatorback belt.

Never squeeeeeeeeled again.

Buddy67Lincoln · March 2, 2008

I've always used the Goodyear Gatorback belt.
Never squeeeeeeeeled again.

I agree. I even told them to use an aftermarket belt and not the junk GM one. The original went bad and then the replacement did...hence the conditioner. They put a third one on so we will have to see. I give it about another month. Thanks

iminaquagmire · March 2, 2008

Aftermarket belts aren't always a cure. That was the whole cause of a similar problem I had on a previous car. My alternator seized and the belt shredded. The shop replaced the alternator and belt and I thought everything was fine. Then the belt shredded again two weeks later, and then again a week after fixing that one. Took it to the dealer and learned that the speced aftermarket belt was actually just barely off in size from the OEM one. They had to pull the engine, and clean all of the pulleys of the melted "correct size" aftermarket belts.

2000DV4.8 · March 2, 2008

I'd also check the A/C belt. I spent months looking for a squeal. The alternator bearings were bad, so that was replaced for free, but I tried a new tensioner, new serpentine belt, and nothing worked. Finally I decided to change the A/C belt for the hell of it, and the problem was fixed.

pm26 · March 2, 2008

Good point. These trucks have a separate A/C belt with its own belt tensioner. The other belt should be checked too. You can run the engine for a few seconds at idle with the large serpentine belt removed. Only a few seconds, as the water pump and the alternator will not be operating.

Now about aftermarket belts. I have had terrible experience with some Auto Zone Mexican made V belts. They constantly loosened and squealed, until tensioned. Then they stretched again and squealed some more.

I got really tired of this and now I buy only good quality belts. NAPA even sells heavy duty commercial truck belts, which are made by Gates and are identified with a green stripe. Expensive, but well worth it.

Buddy67Lincoln · March 2, 2008

Thanks. I guess I will have to put up with it till for a while, but I will have the other ideas listed checked out with the alt, etc. Thanks for the help again guys

MS3DALE · March 2, 2008

The only thing I notice is that my volatage jumps up and down while on the highway. I look at it and over 14 and other times is lower, but never in the red of course. I have to look closer to know exactly what it is when it drops. Could this be a sign? If I am not mistaken, it even jumps over 14, but I know 14V is normal, right? Thanks a lot.

This is normal....

#07-06-03-009: Information on Voltmeter Gauge Fluctuation Due to Regulated Voltage Control System and Concerns About Camper/Trailer Battery Charging - (Dec 5, 2007)

Subject: Information On Voltmeter Gauge Fluctuation Due To Regulated Voltage Control System And Concerns About Camper/Trailer Battery Charging

Models:

2005-2008 Cadillac Escalade Models

2005-2008 Chevrolet Avalanche, Silverado, Silverado Classic, Suburban, Tahoe

2005-2008 GMC Sierra, Sierra Classic, Yukon Models

Voltmeter Fluctuation Condition

Some customers may comment that the voltmeter is fluctuating between 12 and 14 volts on their full size pickup or utility vehicle. Starting with the 2005 model year, light duty full size pickups and utilities are equipped with a new Regulated Voltage Control (RVC) system. This system reduces the targeted output of the generator to 12.6-13.1 volts when in "Fuel Economy Mode" to improve fuel economy. The generator may exit "Fuel Economy Mode" if additional voltage is required. This will cause the voltmeter to fluctuate between 12 and 14 volts as opposed to non-regulated systems that usually maintain a more consistent reading of 14 volts. This fluctuation with the RVC system is normal system operation and NO repairs should be attempted.

Camper/Trailer Battery Charging Concerns

Some customers may comment that when towing or hauling a camper/trailer, the auxiliary battery for the camper/trailer will not stay charged. In most cases, this concern is blamed on the new RVC system. While the RVC system does reduce the generator's targeted output voltage to 12.6-13.1 volts when in "Fuel Economy Mode", this feature is bypassed if the tow/haul feature is enabled. With the tow/haul feature enabled, the RVC system will stay in "Charge Mode" and the targeted generator output voltage will be 13.9-15.5 volts, depending on the battery state of charge and the estimated battery temperature. To keep the generator in the "Charge Mode", use either of the following two methods.

• The first method is to use the tow/haul mode when towing or hauling a camper or trailer.

• The second method is to turn on the headlights, which will increase the generator's targeted output voltage to 13.9-14.5 volts.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

And definetly....NO MORE BELT DRESSING!!! Its not recommended for serpentine belts.

BTW,What part of Pittsburgh you from?