: My water pump belt is dancing around...

04-01-05, 12:56 PM
Every time I get under the hood of my 94 STS, I notice that the water pump belt is one groove either to the left or the right of center on the tensioner. It's never come off and its not wearing out by way of rubbing, but it frequently jumps back and forth by a groove or two. I've wound the motor up many times, run it really hard, lots of WOT and a damn near top speed Nevada run, and its never come off...Any ideas on why it is even moving, or if it is something I should forget about until it does come off?

04-01-05, 01:32 PM
Might be the tensioner, not providing enough tension to the belt..

04-01-05, 01:36 PM
I would check that the tensioner is moving freely and not bound up at the pivot point by rust/corrosion. Remove the bel guard, take the belt off the pulley and exercise the tensioner and lube the pivot point. Sounds like the tensioner is not working correctly. I would replace the belt if it has been doing this. It may have been worn or broken cords in the belt causing it to try to run crooked and jump ribs. It really shouldn't do this at all.

04-01-05, 02:34 PM
There are Continental aircraft engines that drive the alternator with a belt off the rear of the engine. When they start flipping belts off either the dynamic counterweights are locked up or the crank is broken. I remember one engine that broke the crank and the engine stopped turning in one revolution nearly tearing itself from the mounts over the Brooks Mountain Range. The pilot landed power off at the only airfield within 70 miles in one of the most rugged areas on the planet. The pilot had called me on the phone the day before and told me about the belts. I warned him that he was only minures from destruction. I guess he thought I was exaggerating.