The AC belt in my 2003 Avalanche broke in June, I had it replaced by a friend who said the tensioner may have some barings going out on it. So when the belt fell off after that I got a new tensioner and installed it. I was then able to slip the old belt back on. After it fell off again I discovered the bolts holding the tensioner were not completely tight, so I tightened them, and slipped the belt back on. It lasted 2 weeks this time, I put it back on and it fell off the very next time I drove it. Add to this when I turn on the AC I can hear a vibrating or rattling noise at least part of the time. I'm not sure what that could be but assume it has to do with the issue at hand.

SOURCE: Saturn Belt Tensioner...

You probably have a bad tensioner, you cannot tighten a bad tensioner because the bearrings inside have gone bad so your belt will just keep coming off. I had the same problem, don't wait to fix this because your car can over heat, you can lose power steering without proper belt tension. Pay the few dollars now(and I do mean few) and avoid problems later.

SOURCE: mercury villager belt tension

it is possible on some cars to over tighten or under tighten but on your van i believe the tension er is spring loaded which means you cannot over or under tighten because the spring keeps the belt the right tension. and as far as $580 i think that is extremely to high. i don't think you need to replace anything

SOURCE: installing new serpentine belt

if you know exactly what the idler pully looks like and can follow directions I can help you. My help is totally free all I want in return is a fixya rating. I promise to do my best to help you

Mark Glover

• 50 Answers
• Posted on Jun 23, 2009

SOURCE: 2003 Tahoe (5.3). AC belt/tensioner/compressor (Chatters)

The compressor is bad. I have the same problem. Apparently none of the tahoe's compressors are worth a ****! im having to replace mine too. You have to change the compressor, the accumulator/dryer, orifice tube and flush the lines. If you look on ebay you can buy a complete kit to change it all for about 300 bucks. The dealership tells me that you need to change the fan clutch as well. They told me that the reason for the noises is the fan clutch isnt working properly and it lets the compressor get too hot causeing higher pressures in the compressor due to the heat. They called it liquid slugging I believe. Mine doesnt break the belt but when you give it very much gas it makes a squeal and then a grinding noise like your trying to put a standard transmission in gear with it running without pushing in the clutch. I asked if you could just change the fan clutch and they told me no its too late, you have to change the compressor and dryer/orifice tube.

SOURCE: 2005 Nissan Sentra 1.8S, with AC - how to replace belts?

first of all you don't have to loosen the pulley,this will no solve the problem,well you already loosen the adjuster,good,bot thing you have not done i will tell you now,on the power steering pump where the belt pass there is also a bolt that hold it ,you must loosen that also,then after you will see the pump moving on the two position that means you will see the belt loosen on 1 position an d the position it will tight the belt,try that man.............