Alternator and belt question.

[shawnw]

So I replaced the alt. belt on the car last week as it was starting to squeel and was getting pretty badly worn. It was fine for a few days and then I starting to get a whine that sounded like the alternator.

So I went and loosened it a bit but then the belt started squeeling again. I tightened it up a bit more and everything was fine but now I'm getting a whineing sound again. The sound is sporadic. I could drive it for a few days with no issues and then in the middle of a run into town the noise will start up again and then be gone the next time I start the car.

Any ideas? Is my Alt. on the way out or what?

[sanjeet]

Could be the belt isn't tensioned properly and when I do the belt I loosen the bolt under the alternator as well (yes its easy to get at from under the vehicle) the belt will need to be retorqued anyway after a new replacement, Use a screw drive to tension the alternator with about a quarter inch belt deflection, the lock the top bolt and the bottom one.

1. The worst thing is a diode has blown and that can cause a whine, but that is a bit unusual and if it is better to get a second hand replacement.

2. Or bearing problem and maybe its best to do no.1 suggestion

[doylerl]

Not positive, but doesn't the water pump run off the same belt? Have you been leaking any water or has the engine been getting hotter lately? It may be the water pump squeeling.

[shawnw]

Not leaking any water and the cars temp is fine. I'll try playing around with the belt adjustment some more. Could the fact that its been raining for three straight weeks have anything to do with the problem?

[brickdog2000]

I have the same problem. I actually tried to get rid of the squeal by adjusting the tension on the belt while the engine was running. All that did is change the pitch in the squeal. I find it funny cause all I did was take the belt off so I could do my head gasket. So it is the same the belt and it dident squeal until I put it back on. Sorry if i'm stealing your thread shawnw. I just want to figure how to silence the noise too.

[WmWatt]

Try cleaning the belt and pulley. Could have dirt or lubricant on it.

[eurotiva]

Do you still have the plastic deflector (goes from front ,over axle,on back a few inches) under the right side. Totally has something to do with the rain if that's not there.

[brickdog2000]

I might try belt dressing and I still have the plastic on the car.

[blue*93]

is the belt spinning the same way as when you had it on b4? if so, and this is entirely new developement, i'd try new belt and clean all pulleys well with a no residue cleaner. not much cash... i just finished replacing water pump and alt, from tightening belt to get rid of squeel, plus warped pulley... careful.

[brickdog2000]

Well I think I will try belt dressing first and if that doesnt work then I will order a new belt.

[eurotiva]

Ivory soap (bar) works better than any belt dressing. Old school trick.

[David88]

I've had similar problems before. I found two different conditions causing belt issues. The first was rapid belt wear quickly resulting in slippage after repeated tightening. I replaced the belt to no avail. The belt was wearing so fast it left black residue on the alt pulley. I took the alt off and the inside planes of the v groove were rusty and rough. I put a socket with and extension in the hand drill and spun the pulley then held some 100 grit emery cloth in groove till it was shined up well. Re installed the alt with the same belt and its never given a bit of problem since.

The other issue was on a 200 k car with the belt chirping intermittently but no apparent slippage or unusual wear. Just annoying sounds. No amount of dressing or tricks made it better. The same remedy fixed it. Spin the pulley and 100 or 120 emery paper in the groove. I believe it was just too smooth and polished if that make sense and the 100 grit gave it just the little bit of "tooth" to grip and not squeak.

That my experience. Something to look at if nothing else works. Hope it helps.

[miami man]

yep a leaking valve cover gasket on mine oils my belt. too cold to fix now

[Ogrestiva]

Read up on the spec's of the belt in the Haynes manual...I think there is supposed to be 9mm of deflection on the belt...it has pictures on how to measure this.