Tensioner screek 2002 chevy tahoe when AC is on and I accelerate. already replaced tensioner

If it is worse when reving the engine in park, your AC compressor is failing (common problem). The AC compressor, orifice tube, accumulator, belt tensioner and AC belt will need to be replaced and the AC system flushed before recharging.

There is a pulley out of alinement.Check that tensioner and its flush with its mounting surface.Take a straight edge and check one pulley with the other.You can also get on one side or the other of the fenders and look at it to see if any pulleys are out of alinement.

Sounds like tensioner is weak

Sorry to tell you this but if they used a recon compressor it could be bad!! Go and get the system checked to see if you have a leak that happens also and has the same affect. Good luck.

sounds like the belt needs tightening or replacing so yes you are indeed correct about the squeal, as for the rumble depends on how bad the rumble is but it shouldnt be caused by either you mentioned.

hi, there is a published technical service bulletin about this problem for these vehicles and the tahoes. the compressor sitting so low in the system, gets over-run by the liquid freon banging internally and actually locks up on and off during operation. this is the noise you are hearing. apparently there is a screen kit to install in the low side suction line to prevent this from happening, but GM also states the compressor needs to be replaced and the new compressors from GM at least, already have this modification done. So, i replace them when they come into my bay with the complaint you speak of, and the tensioner for the belt, likely the belt too. but it looks like you already know all about that. hope i could help.

I have the same problem and was told that there was a glitch in the compressors from this era> approx 50 % had this problem have changed tensioners and everything only to have same problem of transmission lines chaffing the belt until it breaks. Was told there is a kit you can buy to fix for about $400 otherwise I continue to replace belts. We did put less freaon it it to minimum pressure which did help the cause but will still viberate raiator lines in some cases.

You need to remove the front belt first. Take the tension off the belt by putting a socket or wrench on the tensioner and pivot it away. I would make a quick sketch of the belt route if you don't have a diagram. The AC compressor tensioner is on the bottom and the belt comes off the same way. Installation is the reverse.

My sincere apologies for the severly delayed response.
I am personally going back to answer your unanswered questions.

I do not know if you still need this information, however I am answering it in case you still do.

Click on the following direct Link. It has the Serpentine Belt Diagram for the 2002 Chevy Tahoe for your specific engine and options (AC/No AC etc.). It has other additonal diagrams for your future use. It also has some diagrams on how to rotate/move the Tensioner Pulley/Arm to loosen and remove the Belt.

Standard Rules to Removal the Serpentine Belt:
1. Find the Tensioner(s). (See Diagrams on Link)
2. Using a Serpentine Belt Tensioner Tool, Or Wrench OR Ratchet, Rotate/Move the Tensioner USING THE AVAILABLE NUT OR OPENING (3/8ths or 1/2 inch square opening) rotating it\moving it away from contact with the belt and towards the area where the belt is not in contact with the Tensioner Pulley. The Tensioner is spring loaded, and is hard to rotate/move.
3. Remove the loosened belt off one of the other more easily accessed Pulleys.

Standard Rules for Installing the Serpentine Belt:
a. Pick a Pulley that is most easily accessed. This will usually be on top. This will be the last Pulley that the belt will go on.
b. Using the Diagram: Install the new Serpentine Belt on the remainder of the Pulleys....over, under, left right.
c. Using a Serpentine Belt Tensioner Tool or Wrench or Ratchet Tool: Rotate/Move the Tensioner Pulley/Arm "away" from Belt contact area on the Tensioner. This spring is pretty hard and with a new belt, it will be even harder to install. Rotate/Move this to as-close to the maximum allowed inorder to have enough slack in the belt to get it up and over the last pulley.
d. Using your other hand - Pull the Belt up and over the Last remaining Pulley.
e. Before releasing the pressure on the Tensioner, visually inspect the remainder Pulleys and the Belts' Positioning on them.

Let me know if this helped, or if you have additional information or questions. Feel Free to contact me at FixYa.com!

http://www.2carpros.com/car_repair_information/year/2002/make/chevrolet/model/tahoe/2002_chevrolet_tahoe_drive_belt_routing_diagram.htm

Hello, it sounds as if you have a problem with your tensioner jumping violently. When the defrost is on it uses the ac compressor that is why the belt jumps then to, but it sounds like you are going to be needing a compressor soon. It has a piston that is hanging up at a certain point and thats why it is jumping. It will break a brand new belt when it locks up,when that happens. Please rate my answer, thank you.