Serpentine belt

SWEETIE1965

MEMBER
2004 GMC ENVOY
4.2L
6 CYL
4WD
AUTOMATIC
188,000 MILES

I noticed the belt on my vehicle was getting cracks on the ribbed side so I changed the belt for a Gates belt. Ever since then every belt I put on has tore up with hardly no driving miles. I changed the tension pulley, the idle pulley, and the power steering pump. Still have the same problem. It doesn't matter if the A/C is on or not, it still does the same thing. I did change the thermostat in it a while back in which I had to remove the alternator to change the thermostat. The belt that was on it was getting old with cracks in it. That's why I changed it. Ever since I changed the belt I had this problem. The belt can be put on right, once the engine is started the belt rides almost against the front of the engine block. If the front bearing was going out the engine would make some kind of howling sound or a grinding noise which it's not. I need to get this repaired. It's my only source of transportation. I borrowed a car for a few days but I can't keep using someone else's vehicle. What do you think could be wrong with my vehicle?

6 Replies

JACOBANDNICKOLAS

MECHANIC
108,300 POSTS

Hi,

Since this started when you removed and replaced the alternator, I suspect it is not properly aligned. Once you start the engine, it is jumping off the pulleys.

Do me a favor. Take a look at the pic below. It is the belt routing for your vehicle. I highlighted a section of the belt between the alternator and the power steering pump.

Install the belt according to the pic and then inspect if the belt appears straight between those two points. Based on what you described, it sounds like the alternator is back a bit further than it should be.

Let me know.

Joe

See pic below.

Image (Click to make bigger)

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Saturday, July 17th, 2021 AT 10:09 PM

SWEETIE1965

MEMBER
158 POSTS

That's exactly what I was thinking. I will remove the alternator then install it correctly. I never had this problem until I changed the belt which was about 5 months after I replaced the thermostat. But I will remove the alternator then reinstall it. I will let you know if it fixes the problem.

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Sunday, July 18th, 2021 AT 6:50 AM

SWEETIE1965

MEMBER
158 POSTS

I removed the alternator then put it back in. All 3 bolts for the alternator are tightened down. The belt is riding where it should. On idle pulley and tensioner pulley. All other pullies are in line also. So it was the alternator that was out of line. It's repaired. Thanks again for all your help.

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Sunday, July 18th, 2021 AT 8:44 AM

JACOBANDNICKOLAS

MECHANIC
108,300 POSTS

Hi,

You are very welcome. I'm glad to hear you got it fixed. If you were going through belts as you said, it had to drive you crazy. LOL

Please feel free to come back anytime in the future if you have questions. You're always welcome here.

Take care,

Joe

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Sunday, July 18th, 2021 AT 8:59 PM

SWEETIE1965

MEMBER
158 POSTS

I sure will. Thanks again. It was driving me crazy. I checked all pulleys. They seemed like everything was fine. Until I thought about someone changing the alternator. So that's why I did what I did and it fixed the problem.