Need some help with tensioner pulley

[LoHoe]

I have a 2007 Tahoe. I started to have a squeal every morning when I started it up. Took it by the dealer and they told me to try to change the belt. I swapped it out with the best offered at Advance Auto Parts which didnt stop the squeaking. I then sprayed WD40 on the main tensioner pulley where the bearing is and it would stop. After a few weeks of spraying WD40 on the bearing every morning it stopped working so I went to Advance Auto Parts yesterday and purchased a whole new assembly. I installed it and when I started it up and the squealing was back so I popped the hood and sprayed WD40 on the bearing of this new pulley and it went away. Called Advance this morning to tell them that the new assembly is squealing too and they told me that now it may be something else causing the squealing but they will swap out the assembly with a new one for me just incase the one I bought yesterday is bad. Dont understand how it could be something else when I spray WD40 on the bearing on the pulley and the squealing goes away. Please can someone help me with this problem and tell me what should I do now. I would appreciate it

 

[InTruckDesign]

Take the belt off and wash it with dishsoap, will take any oil,grease,crap off of it.

 

[LoHoe]

Take the belt off and wash it with dishsoap, will take any oil,grease,crap off of it.

Yesterday I took the tensioner pulley assembly off and brought it back to Advance Auto Parts to return it. Then I went to O'Reilly's and bought a Gates tensioner pulley assembly to put on the Tahoe. I also did like you said and washed the belt in dishsoap. Get in the tahoe this morning to leave for work and still have the same result as before which means I had to pop the hood and spray WD40 on the tensioner pulley so it would stop making noise. I really dont know what else I can do to fix this problem. What else would make the noise and when I spray WD40 on the tensioner pulley bolt and bearing area it would make the noise go away. Tired of hearing that noise every morning and having to pop my hood to spray WD40 on it.

 

[InTruckDesign]

When you spray the WD40, is the motor running or off?

It"s hard to accept that 2 brand new tensioners are squeeking...maybe pull the bolt you are spraying and give it a nice even coat of anti-seize then re-install.

 

[LoHoe]

When you spray the WD40, is the motor running or off?

It"s hard to accept that 2 brand new tensioners are squeeking...maybe pull the bolt you are spraying and give it a nice even coat of anti-seize then re-install.

I spray it while it is running. I know its hard to believe it too. I might have to try that. Anything before I bring it to a shop