BadDog

Not exactly boat related but could prove useful on newer serpentine belt applications.

I have a Tahoe with the Vortech engine, which uses a serpentine belt setup. There is an idler for the belt and a tensioner. Each of these pulleys has sealed bearings. The truck developed a squeal and squeak that I was having trouble isolating. The noise definitely sounded like one of these sealed bearings gone bad. The noise would quit when it warmed up though.

To narrow down which pulley was squealing I tried forcing some oil into the area of the sealed bearing but as it was still somewhat sealed this did not work. I tried the stethoscope but the noise just transferred to the block and everything attached. Checked at GM to see which part they sold more of, it was about 50 50 so no help there.

Had another idea I thought I would try. Filled up dish soap bottle and shot a steady stream of water at one of the pulleys. No change. Shot the other one and the noise subsided as long as the water stream was on the pulley. Theory being that the water dampened the harmonics of the bad bearing and made the noise stop.

Now some of the more astute readers will say that the belt was squealing but I shot the belt first with no change.

Just thought I would pass this along.

Tim T.

HARRISONMIRAGE

I have seen similar problems on serpentine setups if the belt has ever been sprayed with anti slip.It fills the grooves like resin an doesn't let the belt seat properly.Usualy if it is a belt or allignment problem a shot of wd 40 on the belt will quieten it up for a very short while,but at least you know if its bearing related or not.

mcollinstn

You can usually get WD40 to penetrate the bearings on the idler pulley well enough to keep er quiet for a month or so. Just use the little red tube and squirt it in while it is running at fast idle.

For whatever reason, I've noticed that it is usually the outer bearing.

BadDog

More exposure to the elements on the outer bearing...

mcollinstn

Makes sense.
Quarter car wash probably gets most of them.

Just read a Benz service bulletin that re-emphasizes that the only approved method of cleaning an engine bay on a Benz is with a low pressure steam cleaner.

Advises that any dealership that finds that the waxy (cosmolene) protectant has been blasted off an engine should advise the customer that any failure due to water intrusion on the engine components might not be covered under warranty. The newer motors don't have that waxy coating, so there is not a visible indicator to use..

I'm guilty. I've blasted a blue zillion of them with 10,000 psi over the years...

BadDog

We used to run trucks in water so deep the de-froster would spit mud. Never had any failures but they were pretty simple. Only trouble was starters. Several times I had to extract a starter from a running truck in order to install it on another to get it going after stalling or stopping for a beer/pee break. I guess I will put he new part on and keep stay away from the car wash.

Wally

iTrader: (1)

the SBC Vortec motors from 96-99 have a problem with the tensioner pully bearing going bad. Its a very common problem on these motors. Most dont last more then 75-100k miles... And i have heard of many others going sooner then that. Another problem on the Vortecs is the alternator...mine konked out at 90k I guess when you start hovering around 100k miles you should expect things to start going out.....but if its a newer truck that has mostly highway miles then WTF???

BadDog

My alternator quit on the way to the lake when it had 98K on it. I did not consider it a big deal until I went to buy the replacement. I forget how much it was but I do recall it was stupid high. That and the $8 dollar plugs makes ya wonder.