So I'm driving to the moutains today and just entered the foothills when my AT Oil Temp warning light comes on accompanied by a loud squeal. Like an ass my music was turned up loud so I have no idea what, if anything, was happening with my truck before this. I pulled off the road immediatly and the truck stalled. Its now back at my house via tow truck and it starts up fine and shifts in and out of gear. Turns out the squeal is the water pump pulley not turning. Is this common when they fail? What am I looking at here? Also, how is this related to my transmission temp? The water temp wasn't high when I pulled off the road either. Also, the transmission fluid smells burnt but I gather thats going to happen when the temp gets up there. Any suggestions as to whats going on here?

 

Tranny is cooled Via water circulating through the radiator, around the tranny cooler. If the pump is not turning, water is not circulating, and thus not cooling your Transmission.

Btw, change your trans fluid and filter since you overheated it. Heat is a trannys #1 killer.

 

ok, so that explains the overheating. Why then did my water temp not shoot up? Is it because without water moving away from the engine there was no excess heat to be detected?

 

dunno why that might be. It was prolly in the process of overheating, but becuase the trans was working hard up the hill, it overheated faster.

 

I guess so. So when water pumps fail do they usually just sieze completly?

 

Is it actually the water pump, or the pulley that drives the fan. The water pump is behind the timing belt and is driven by that. The pulley in front that has the drive belts on only turns the fan. It's well known for siezing, and not cheap to replace. If the fan stops the engine will overheat, but maybe the tranny overheated first and you stopped before the guage went up.

 

Yea, I didn't think about it being the fan support. Same concept, except with the fan not turning, it would over heat that way instead of through no coolant flow.

 

Yeah it seems to be the the pulley that drives the fan. I just assumed that was connected to the water pump behind it. Is it not then? Does he problem lie with the pulley? I'm confused now, sorry.

 

What you are talking about is the fan support bracket. The water pump is on the lower left corner of the engine.

The fan support to those engines is known for failing. The bearing seizes up. Do a search on here for Fan support bearings/brackets, and you will have your answers.

 

This thing is the fan support bracket:

 

ahhh, all clear now, thanks for your help.

 

so there is a bearing inside that bracket that has presumably failed?

 

Yep. Consider yourself lucky that you caught it before it had the chance to do real damage. Sometimes when that bearing seizes, it will break off and your fan will destroy your radiator, among other things.

That pulley bracket (pictured above) runs about $700 from the dealer. You can find 'em much cheaper on ebay. I believe napa has them for less than $200.

Search the forum. This has happened to quite a few people here.

 

Yeah, I'm begining to wonder if an electric fan wouldn't be more reliable.