Serpentine belt - Sheared Waterpump then tensioner belt

Hi All,

I have a problem with the serpentine belt still after 2 yrs of trying different things. My tensioner (which I replaced) still jumps on tickover upto about 2000 revs. So Far the waterpump shaft has sheared and more recently the bolt holding the tensioner on. I've read up on previous threads and I'm blaming the penny trick on the tensioner bolt shearing, which I did because of the excessive squealing. The waterpump i reckon was down to the movement on the tensioner.
I have changed all the pulley wheels, new power steering pump, waterpump and all of them are nice and free when I move by hand so I can't understand the movement. I've had a look at all of my friends 300's and their tensioner doesn't move a bit!.

So apart from advice on the above, I no longer want to use the penny trick, but I don't see any alternative - maybe high tensile bolt?

All Advice appreciated as I no longer feel confident in my trips to morroco.

Thanks

Mark

you need to check all idlers are free and not seizing,stud for tensioner needs to be in tight 2 nuts locked together will ensure that ,you shouldnt need penny trick if all parts are serviceable ,its possible you had poor new tensioner fitted

Yeh, thanks James, all idlers are fine. This is the second new idler now?

is crank pulley running true all grooves on pulleys fine ,nut on tensioner stud tight ,cheap pattern tensioners

Hi James, yes to all of that except for the tensioner. It's a cheaper one from Paddocks. I've just asked Noel for the OEM Dayco price and it's £56 so think I'll try that to iscolate the problem even further.

I fitted a new water pump to my '96 300 tdi this afternoon after a bearing collapse : also fitted a new serpentine belt but now it keeps edging off the WP pulley by about two mil, just enough to sit on the flange of the pulley where it's likely to get shredded. I've tried and tried to get it back in line but after re-starting the engine it waits about five seconds before going off-line again. Am I missing something here> Is it so bl... difficult to straighten up? Can the belt be on the wrong way round>? Could a problem with the water pump pulley have caused the pump to fail and therefore I need to change the pulley or should I change the pulley because it's been damaged by a knackered water pump?

sure its not the viscous fan pulley? the horrible one in the timing cover?

i found that with the aircon belt, and the main belt, it could fail, and still work to a degree. you have to take both belts off to properley check it. it adds to the slop in the belt, and because the tensioners are not usually that great, the slack allows it to yank the belt, and keep the tensioner from settling smoothly.