Mechanics

BELT TENSIONER RATTLING

1999 Ford Explorer • 216,000 miles

Hi, my explorer runs perfectly fine but when you run the ac the belt tensioner freaks out and makes a rattling noise. It will only do it in reverse or drive. The belt tensioner and ac clutch are perfectly fine. When you turn the ac off, the rattling noise quits. Also, when you shut the vehicle off, you can smell a burning smell. The gas mileage has gone down a little bit. Any ideas because I am at a loss?
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Rmoore09
July 3, 2012.




Your belt tenisor is going out its weak thats why its doing what its doing.


Saturntech9
Jul 3, 2012.
The belt tensioner has been replaced twice to fix the problem. It still continues to rattle.


Tiny
Rmoore09
Jul 3, 2012.
What brand belt tenisor are you using?I have seen multiple brand aftermarket belt tenisors rattle replace with a different brand and rattle again. Then put a factory one on and rattle stops. Also sometimes the incorrect belt size or a cheap thin belt can make the belt tenisors rattle.


Saturntech9
Jul 3, 2012.
Especially with the ac on and in gear they can rattle pretty bad.


Saturntech9
Jul 3, 2012.
So I need to replace the belt and the belt tensioner with the OE brand?


Tiny
Rmoore09
Jul 3, 2012.
What brand belt tenisor and belt are you using?


Saturntech9
Jul 3, 2012.
Idk actually on the belt, its only been 10000 miles on the new belt. The tensioner was Oreilly house brand. What brand do you suggest?


Tiny
Rmoore09
Jul 3, 2012.
I would use a motorcraft belt tenisor and a dayco belt. Do you have a 4.0L Ohv or a 4.0L sohc?


Saturntech9
Jul 4, 2012.
4.0 OHV
AD


Tiny
Rmoore09
Jul 4, 2012.
Just to add, ake sure the ac compressor is not momentarily locking up causing this issue.

Roy



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