thumping sound

[MLAinSD]

Ok, here's the deal.....when I have the a/c on and the Liberty in gear, I started hearing a "thumping" sound when I am stopped. It is not a knocking or ticking....the best I can describe it is a faint thumping sound. If I turn off the a/c it seems to go away. If I shift to neutral or park it also seems to go away. I don't hear it at initial start up, but when I'm driving around I notice it when I have to stop. I'm thinking it maybe the a/c compressor?

Anyone else have this noise?

I brought it to the stealership yesterday to get diagnosed....a $110 diagnosis fee (which would be put towards any repair if authorized, of course)!! Wow, I asked if the diagnosis fee was standard and the guy said "yes, depending on what the request was for". FYI - I also asked them to check the rear doors because of excessive wind noise, which I cancelled once they said they would charge me $110 diagnosis fee for that too!!

 

[CzarKJ]

Could be the pulley/clutch that the AC uses. Check for play in it. But a thumping I think would indicate worse...

 

[MLAinSD]

Ok, so I finally got a call from the dealer and they said there was a noise and they recommended replacing the tensioner pulley (and belt while I was at it). It would be $165 parts + $246 labor. Yikes! Seems like a lot to charge considering tensioner pulley and belt replacement can be done in about 20 min.

 

[CzarKJ]

Ya I did mine for about 100 total from napa and 5 minutes. (4 to drink the beer)

 

[CactusJacked]

At rockauto.com, $42 for a Gates tensioner, $22.79 for a Goodyear belt, -5% discount, plus shipping. You can cheap out on the belt and save up to ten bux, but I wouldn't. If you're not able to do the job yourself, you're at their mercy, plus you're already into them for $110 for their (probably) 5-10 minute evaluation. However, I wouldn't have taken it to a dealership for the obvious high labor rate reasons you're showing. But then, I never take anything to a shop.

 

[MLAinSD]

My Rock Auto order submitted!

I just hope this will resolve the issue....but at 107k miles, its not a bad idea to change the tensioner pulley anyways.

But I still think it may be the a/c. I'll keep my fingers crossed.

 

[tjkj2002]

My Rock Auto order submitted!

I just hope this will resolve the issue....but at 107k miles, its not a bad idea to change the tensioner pulley anyways.

But I still think it may be the a/c. I'll keep my fingers crossed.

I'd skip any goodyear belt,old style poly belt and not worth it Get a Gates EPDM belt(also known as Micro V),it's worth the cost and will last 3-4 times longer then a poly belt.


Make sure you replace the whole tensioner,not just the pulley,as the internal spring is your issue.Been there done that with that noise when at idle(in gear) with the AC on,and yep it was the tensioner.

 

[MLAinSD]

I'd skip any goodyear belt,old style poly belt and not worth it Get a Gates EPDM belt(also known as Micro V),it's worth the cost and will last 3-4 times longer then a poly belt.


Make sure you replace the whole tensioner,not just the pulley,as the internal spring is your issue.Been there done that with that noise when at idle(in gear) with the AC on,and yep it was the tensioner.

Yep - got the Gates belt and belt tensioner (whole thing). I also got some small stuff (air filter, etc). I'll install it and post an update - hopefully that the issue is gone.

 

[MLAinSD]

Ok, I got everything in and now I can't take the darn 13mm bolt off! The head is a little rounded and my socket keeps sliding off

 

[CactusJacked]

Try a 1/2" socket, it's a hair smaller than 13mm but still fits.

 

[tjkj2002]

Ok, I got everything in and now I can't take the darn 13mm bolt off! The head is a little rounded and my socket keeps sliding off

Get the engine up to operating temp and then like CactusJacked stated use a 1/2" 6 point socket.May have to tap it on and when you get it out put antiseize of the threads before re-installing.