: Alternator Replaced, Now Belt Squeaks, How to Fix?



digitalcaddie
12-11-06, 11:06 AM
So my mechanic just replaced the alternator on my '97 SLS and now I've got a really bad squeak from the serpentine belt. Did I get a bad part? After the engine gets warm, the noise goes away while idling which leads me to believe the problem is not the alternator bearings. But as soon as I speed up the engine (in gear or neutral), the squeak gets pretty bad. If the pulley is out of alignment, how do you fix/adjust that? I like the car, but it seems like I can't go 30 days without fixing/replacing something... Thanks in advance for any help/suggestions. -digital

eldorado1
12-11-06, 11:35 AM
count the number of grooves on the alt pulley. Should be 6.

clarkz71
12-11-06, 02:32 PM
I could just be the mechanic got some grease on the belt while re-installing it.

digitalcaddie
12-11-06, 02:54 PM
OK...so if my mechanic got grease on the belt, whats the best way to clean it off? I read a couple posts saying put belt dressing on the belt, but several people had theirs squeaks get worse with too much dressing. So if thats the way to go, then how can you tell if you get too much on there?

The number of grooves in the alternator pulley is the same as the number on the belt.

zonie77
12-11-06, 03:28 PM
Look at the belt, do you see evidence of grease or oil? Is it slick, shiny, or cracked and hard?

If it's in good shape clean it with some type of cleaner (Alcohol, small amount of carb cleaner or brake cleaner) and apply some belt dressing. If you can take it off you can clean the pulleys better and check for noisy bearings.

You don't soak it in belt dressing. A few quick shots in various spots around the belt is all you need.

Ranger
12-11-06, 05:52 PM
Why not take it back to the mechanic who replaced it and let him clean the belt?

digitalcaddie
12-11-06, 06:23 PM
Good point, Ranger. Problem is my mechanic's shop is 45 minutes from my house or work which isn't very convenient. The guy's honest and much cheaper than the dealer so thats why I go to him although in this case it appears like I got what I paid for (ie the alternator is installed, but maybe his carelessness caused this other problem).

dp102288
12-11-06, 09:19 PM
Yeah I was going to say take it back but it is kinda far...

My car squeaks in the cold too...I just never bothered to fix it. Never did any major repairs to the engine though. I know if I put some water on the belt when it is spinning the sound goes away. Not sure if that means anything (grease, needs lube...)

Ranger
12-11-06, 10:04 PM
Well, that being the case, make sure that the belt tensioner is applying enough tension. Then remove the belt and clean it soap and water or some type of degreaser. You could do it on the car by releasing belt tension, moving the belt and cleaning a section, then move it again and clean til you get the whole belt done.

eldorado1
12-11-06, 11:44 PM
Or you could just replace the belt... I think they're about $20.

I had a squeek I couldn't figure out... new belt fixed it. Tried everything and a half to get rid of it... new tensioner, idler pullies...

dkozloski
12-12-06, 12:48 AM
Or you could just replace the belt... I think they're about $20.

I had a squeek I couldn't figure out... new belt fixed it. Tried everything and a half to get rid of it... new tensioner, idler pullies...
Hold a bar of soap to the grooved side of the belt long enough for the belt to go all the way around a couple of times. It's been the standard fix for a squealing belt for a hundred years.

eldorado1
12-12-06, 11:28 AM
and saw dust will fix a slipping tranny.....

what's your point?

clarkz71
12-12-06, 11:53 AM
Hold a bar of soap to the grooved side of the belt long enough for the belt to go all the way around a couple of times. It's been the standard fix for a squealing belt for a hundred years.

Or...... you could just replace the belt. I agree with Eldo on that.

dp102288
12-12-06, 12:05 PM
I would be scared the soap would cause it to slip...I say change too.

ewill3rd
12-12-06, 01:13 PM
Don't smear or spray anything on the belt.
That will only be a temporary repair. The pulleys should be clean and dry.

Typical things that cause a belt to squeal are pulley misalignment, improper belt installation, or contaminants such as belt dressing or coolant.
Make sure the grooves in the belt align with the grooves in ALL the pulleys. Sometimes one will move over a groove and will cause the belt to pull between two pulleys, making it squeak.
If all the pulleys look good and the belt is on all the way you might just consider replacing the belt.
Contamination on a N* is not really an issue since the coolant is on the back mostly. Dex cool can be a real squeaker if you get it on the belts.
If your alternator is one of the ones that is liquid cooled, then it's possible homey got Dex all over it.

If the belt is installed properly and the tensioner looks good, I'd replace the belt.

dkozloski
12-12-06, 01:15 PM
The soap trick is good science. A small amount of soap will cut the glaze on the belt and give traction with the pullies. It's hard to argue with 100 years of success. If it squeals again in a month or two it only takes seconds to do it again. What have you lost if it doesn't fix the problem?

ewill3rd
12-12-06, 01:29 PM
koz, I would agree that at this point he's not really risking much.
I'd say of all the stuff you could smear on the belt that's probably the least harmful.

Serpentine belts don't share a lot of characteristics with old V belts, they are both black and drive accessories but there are things I would try with V belts that I wouldn't with Serp belts.
I always try to recommend permanent fixes, not things that involve smearing whatever you can find in your bathroom cabinet on your car. :D

I am not knocking your advice, just offering my own.

dkozloski
12-12-06, 03:29 PM
koz, I would agree that at this point he's not really risking much.
I'd say of all the stuff you could smear on the belt that's probably the least harmful.

Serpentine belts don't share a lot of characteristics with old V belts, they are both black and drive accessories but there are things I would try with V belts that I wouldn't with Serp belts.
I always try to recommend permanent fixes, not things that involve smearing whatever you can find in your bathroom cabinet on your car. :D

I am not knocking your advice, just offering my own.
As a matter of fact, a serpentine belt is a connected collection of V-belts operating in parallel. The accepted name in industrial applications is poly V-belt drive. About the only major operating difference from an ordinary V-belt is that a serpentine belt will better tolerate an idler on the back side that bends the belt backwards.

MonzaRacer
12-17-06, 11:05 PM
Well as a tech also I would use sopa to see if it was contamination, if it goes away and doesnt return in coupleof months it was contamination if it comes back its probably a combination of weak tensioner and shined up belt.
Most belt comebacks I get are fixed with new tensioner/belt. if it had over 20 k on belt and got a new alt then squeaks it can be either belt orr tensioner(if not previously replaced or high miles) OR it can also be paint from new alt pulley as some are painted by cheap rebuilders(as GM/AC Delco actually spec them as being black anodized/black cad plated) I actually prefer to also get pulleys glass beaded if i have continual problems with customers cars.
Good Luck
Lee

dkozloski
12-18-06, 09:08 PM
Well as a tech also I would use sopa to see if it was contamination, if it goes away and doesnt return in coupleof months it was contamination if it comes back its probably a combination of weak tensioner and shined up belt.
Most belt comebacks I get are fixed with new tensioner/belt. if it had over 20 k on belt and got a new alt then squeaks it can be either belt orr tensioner(if not previously replaced or high miles) OR it can also be paint from new alt pulley as some are painted by cheap rebuilders(as GM/AC Delco actually spec them as being black anodized/black cad plated) I actually prefer to also get pulleys glass beaded if i have continual problems with customers cars.
Good Luck
Lee
:yeah:

digitalcaddie
12-19-06, 11:44 AM
I've tried the soap trick and it works very well...for about 1 trip and then the squeak comes back. So it appears like the squeak is due to some large contamination. I'll try to give the thing a thorough cleaning over the holiday and see if that takes care of it. If not, replacement belts are not that expensive and are definitely worth it since the N* is a very quiet engine when working properly. Only problem now is I don't have the car after I got towed last weekend (mis-read a snow route sign) and the stupid tow truck driver slammed my bumper so hard, the entire front cowel got pushed into the front tires. Guy at the body shop estimated $1000 worth of damage...I'm not having a good month with my car.

dp102288
12-19-06, 12:34 PM
^^ Damn that damage sounds pretty bad. :(

Ranger
12-19-06, 05:58 PM
I hope those road pirates are going to be paying the repair bill. :want:

ewill3rd
12-19-06, 06:25 PM
Seems like the accident damage could have affected the belt, maybe you'd better have the body shop check that when they get the car straigtened out, I think that guy needs to replace the belt!

dp102288
12-19-06, 08:43 PM
Unless its mostly cosmetic, $1,000 seems to low of an estimate for the repairs to me. Anyone else think so?

digitalcaddie, what's the extent of the damage?

Ranger
12-19-06, 09:27 PM
If it's from towing, most likely it's the lower fascia. Not hard to reach $1000, parts, paint & labor.

dp102288
12-20-06, 10:28 PM
^^ Oh the car was being towed and the two truck stopped to suddenly, slamming the Caddy into the truck?

I still think $1k is too low. digitalcaddie, I would just get other estimates just to make sure you get enough money to cover the damages.

Jmacias
01-02-07, 03:00 AM
The new alternator may have a pulley that's slightly smaller, causing the belt to slip. Have had this problem with A/C Delco alternators. The new a/c delco belts are slightly shorter than the originals, putting more pressure on the pulleys & stopping the squeeks.

GreenMachine
01-02-07, 08:15 AM
I'll be damned, my waterpump belt and my main belt both had a squeak that would come and go, the soap thing seems to have stopped it, the squeaks popped up after I had done the Coolant change this summer and it got a little messy at one point :P