XK8 serpentine belt problem

franksm

Okay folks, what do you make of this ? Serpentine belt/tensioner pops. Only happens on the first cold start of the day. Then it settles down and is perfect thereafter.

The tensioner and the idler pulleys have been replaced, and the belt is new. All Jaguar OEM parts. In fact the tensioner was renewed again, in case the new one was the problem.

Before this, the car threw the belt once. One of the pulleys was noisy, hence the need to replace the tensioner, idler and belt in the first place.

Alternator is about 2 years old, the power-steering pump is about a year old. Aircon was switched off, and is the original unit. Water pump pulley seems fine, history is unknown, could well be the original. Crank pulley looks okay to the eye and is original. All pulleys and bearings feel okay to the touch, so nothing obvious amiss really.

Car is a 1997 XK8

https://www.youtube.com/watch?v=isBMXplWhwE

dhog4n

I can't offer any ideas other than a problem with the belt itself. There were several upgrades made to the tensioner and belt configuration over the life of the xk8, some more sucessful than others.

I use jaguarforums.com for questions about our xk and find it brilliant. Someone on there will have an answer for you.

The link for their xk8/xkr subforum is:

http://www.jaguarforums.com/forum/xk8-xkr-17/

gctest50

about 12 seconds in you can see weirdness at the alternator ( causing the tensioner to move over n back )

https://www.youtube.com/watch?feature=player_embedded&v=isBMXplWhwE#t=12

like the belt is too narrow/ has lost one of its "ribs"