Alternator / Water Pump Belt

agro1 · #1 (**permalink**) 10-11-2002, 07:25 AM

...Mine slipped off yesterday when I was doing a little speed run - all the way through 2nd, 3rd and halfway through 4th. Noticed the ignition/alternator light come on, checked the amameter, no charge. Checked the water temp guage - skyrocketing up past 120 C - shut 'er down immediatly and pushed it home (wasn't far).
Belt was fine, steam venting out of the radiator cap...Switched on the cooling fans and let'er cool down. Loosened the alternator bracket, slipped belt back on (it was in perfect shape) and pryed the alternator back into position with a crowbar. Filled it back up with water and started it up. I let it idle for about 10 mins and the water temp stayed right at 80 C, totally normal. Took it out for a nice mellow test run and everything was fine, no smoke, water temp stayed at operating temp - Looks like I dodged a bullet...

Is this normal for the belt to come off ? Has anyone had this happen and is there anything I can do to prevent it from happening again like an aftermarket belt tensioner ??

Also, could I have damaged anything from the overheating and lack of coolant flow ? It only ran without the belt for maybe 5 mins max. Thanks in advance guys.

Mr.Fixit · #2 (**permalink**) 10-11-2002, 08:07 AM

If your pulleys are not correctly aligned, this can become frequent. I had a bent alt bracket on an old BBchevy that kept causing the fan belt to turn over every time the motor saw 6000. It would stay on the pulleys, but the V was pointing the wrong way. Got out the straight edge, found the offending pulley, straigtened the bracket and problem was solved.

ERA535 · #3 (**permalink**) 10-11-2002, 08:10 AM

agro -

How does it run and start? If OK then you are probably fine.

Perhaps a combination of the belt not being tight enough and the pulleys not being lined up accurately enough caused it to be flipped off.

agro1 · #4 (**permalink**) 10-11-2002, 08:48 AM

Starts fine - runs fine...No problem. Water temp stays nice and cool (unless I rip on it). I was told that if it runs fine and the temp ok then it is fine, and that if it had blown (another) a head gasket I would know (water temp skyrocketing). Did I dodge a bullet or what ???
I think I'll go have the pulley allignment checked before I put it on the chassis dyno this afternoon...
Any thoughts ??

Oh yea - It's amazing how much help you get from joggers, walkers when they see you pushing a Cobra !!!

Excaliber · #5 (**permalink**) 10-11-2002, 09:22 AM

You dodged a bullet by taking quick action, you done good! I bet the engine is fine. Don't over tighten the belt now, thats hard on the water pump pulley you know! Check pulley alignment, that was a good call.

Ernie