Alternator squeal after engine start

[92EcoDiesel Jetta]

Anyone get the alternator squeal after every engine start? I've tightened the belt and it still squeals but I don't want to tighten it anymore since I don't want to shorthen the life of the bearings. I've been taking current measurements and to my surprise, the squeal is not due to high amperage loading of the glow plugs but rather from the alternator surge (around 45 amps) charging the battery. I disconnected the glow plugs, started the engine and it still squealed while the ammeter indicated 45 amps! As the ammeter reading drops over approx 3 to 4 seconds, the squeal stops. I am trying to find a work around since it is annoying as hell!

[R.O.R-2.0]

buy a new belt. your old one is glazed. pullies may be also..

[92EcoDiesel Jetta]

buy a new belt. your old one is glazed. pullies may be also..

Belt has less than 1500 miles on it although it did squeal for a long time before I adjusted it so it is probably glazed and should be replaced. What are sources of new pulleys?

[vanbcguy]

Sometimes a little emery cloth on the pulleys can help.  You don't really want a rough surface though as it will wear the belts prematurely.

Also make sure you really do have the correct belt - VW belts are all metric so just buying one that 'looks' right doesn't necessarily mean it is actually the correct taper.  Metric V-belts have a different taper than SAE V-belts.  They're close enough to seem like they fit but they don't really work right and will slip, etc.

[larry104]

I had the same problem with the same model/year car. It's not the belt or the pulleys. I replaced the belt multiple times as well as the idler and alternator pulleys. It's the design. Tightening the idler reduces the wrap angle on the alternator pulley, which make the belt slip more. The belt glazes, overheats, then snaps.

Here's how I fixed the squeal...

http://www.vwdiesel.net/forum/index.php?topic=29090.0

My setup has 3,600 miles so far and NO squeal. I'm thinking of making a kit for those who don't have access to machine tools.

[R.O.R-2.0]

do you have a/c?

that small belt is the problem if you are running a/c.. look at how thin it is..

im running non a/c, and my belt has a smaller bite (wrap angle) on the pulley, and slips. but thats because i have an SAE belt on a german car..

[wdkingery]

I get a squeal sometimes. UT its not belt. It's bearing some way. Someone said might be timin belt pulley.

My damn a/c. Compressor won't stay tight for the life of me!

[R.O.R-2.0]

I get a squeal sometimes. UT its not belt. It's bearing some way. Someone said might be timin belt pulley.

My damn a/c. Compressor won't stay tight for the life of me!

you really need to make sure its not the timing belt tensioner. when they start talking to you, they are saying

"HEY, CHANGE ME BEFORE I WRECK YOUR ENGINE!!"

when that tensioner seizes up, it starts melting the backing off the belt, then when it wears thru enough, the belt snaps, and your engine is trashed..

CHANGE IT!! or atleast make sure its not the culprit of the noise before it locks up and you get the clash of death..

[larry104]

do you have a/c?

that small belt is the problem if you are running a/c.. look at how thin it is..

im running non a/c, and my belt has a smaller bite (wrap angle) on the pulley, and slips. but thats because i have an SAE belt on a german car..

Yes, car has A/C. I tried three different belts, including the Dayco part number that's on there now (best of the bunch). The Dayco, without the additional idler, needed adjustment within a couple weeks and lasted only a few months. The current setup uses the Dayco belt as well. I've not adjusted it.  The belt is still tight and shows no sign of distress after 3600 miles, which is since mid-May.  I'm fairly sure the problem is fixed.

[Smokey Eddy]

I can rarely get my alternator pulley to stop squeeling and I can't find a new pulley for any reasonable price so i take the pulley off about once ever 2 years and completely sand it down with 40 or 60 grit inside.
new belts also help. V-belts are just a poor design. I'm tempted to run a chain. - would also sound AWESOME

[jettabrendan]

to be honest you think the germans would have been smart enough to not use v belts and mechanical tensioners, they are the worst f**king  thing to ever use in a vehicle. ive gone through 3 belts this month. the only true way to get rid of this problem would be to either swap to serp or drop in an aaz. it just happened to me again tonight coming home from the drive in, if i dont sit there for 5 min untill my tach starts working, the belt snaps, u can smell burning rubber. so amazingly aggravating that it makes me want to put a brick on the pedal and run it off a cliff. it helps if the pullies line up, usually have to find a old alternator to find shims because they stopped including them with new alts.

[nathan_b]

I can rarely get my alternator pulley to stop squeeling and I can't find a new pulley for any reasonable price so i take the pulley off about once ever 2 years and completely sand it down with 40 or 60 grit inside.
new belts also help. V-belts are just a poor design. I'm tempted to run a chain. - would also sound AWESOME

way back when the 36hp beetle land speed record was set by a guy running a supercharger off a bicycle chain...

never failed and he was turning like 7krpm. lol

[larry104]

to be honest you think the germans would have been smart enough to not use v belts and mechanical tensioners, they are the worst f**king  thing to ever use in a vehicle. ive gone through 3 belts this month. the only true way to get rid of this problem would be to either swap to serp or drop in an aaz. it just happened to me again tonight coming home from the drive in, if i dont sit there for 5 min untill my tach starts working, the belt snaps, u can smell burning rubber. so amazingly aggravating that it makes me want to put a brick on the pedal and run it off a cliff. it helps if the pullies line up, usually have to find a old alternator to find shims because they stopped including them with new alts.

Cold start of my Ecodiesel...

http://www.youtube.com/watch?v=ZHVXbKD5IPk

...No squeal.

[Mark(The Miser)UK]

to be honest you think the germans would have been smart enough to not use v belts and mechanical tensioners, they are the worst f**king  thing to ever use in a vehicle. ive gone through 3 belts this month. the only true way to get rid of this problem would be to either swap to serp or drop in an aaz. it just happened to me again tonight coming home from the drive in, if i dont sit there for 5 min untill my tach starts working, the belt snaps, u can smell burning rubber. so amazingly aggravating that it makes me want to put a brick on the pedal and run it off a cliff. it helps if the pullies line up, usually have to find a old alternator to find shims because they stopped including them with new alts.

Or buy a Quantum. In about 18 years of driving them, I don't remember changing an alt belt. An alt or 2 yes! Maybe it's an A/c thing. Never ever seen an A/C equipped Q in the UK, although I do have a set from USA in the cupboard

[92EcoDiesel Jetta]

to be honest you think the germans would have been smart enough to not use v belts and mechanical tensioners, they are the worst f**king  thing to ever use in a vehicle. ive gone through 3 belts this month. the only true way to get rid of this problem would be to either swap to serp or drop in an aaz. it just happened to me again tonight coming home from the drive in, if i dont sit there for 5 min untill my tach starts working, the belt snaps, u can smell burning rubber. so amazingly aggravating that it makes me want to put a brick on the pedal and run it off a cliff. it helps if the pullies line up, usually have to find a old alternator to find shims because they stopped including them with new alts.

Cold start of my Ecodiesel...

http://www.youtube.com/watch?v=ZHVXbKD5IPk

...No squeal.

Nice! Is adding the roller tensioner the only change? Did you keep the stock tensioner?