Alternator on 2002 VW Golf

westenburgdan

New member
Joined
Jan 20, 2020
Location
Michigan
TDI
2002 VW Golf
The Alternator is still producing over 14 volts, but is making a terrible noise, which just became noticeable in the last few days. Maybe alternator clutch needs to be replaced but not alternator? Not sure.

When I look at you tub videos of alternator replacement, the radiator fan, air compressor, belt tensioner, belt, side splash guard, tire, etc. all get removed. My TDI just turned over 180,000 miles, and I suspect that the alternator was never replaced / original equipment, but not sure. I watched it run with the hood open, and there are sparks that happen periodically inside the red wire windings of the alternator, and a wooden dowel for a stethoscope tells me that it is the source of the vibrations and sound.

What also needs to be replaced along with this job while I am at it? the air conditioning compressor I have never run since I bought the car just shy of 163,000 miles. Living in Michigan, I just roll down the windows and wait for colder weather, which always comes. Is there a configuration for by-passing the air compressor with a smaller serpentine belt?

My goal with this golf is to get it to over 300K. It is a manual transmission. I read in another thread on TDI club that the alternator should be a 120A for manual and 90A for automatic? My golf is basic. I don't have a lot of amp draws with extra stuff added to the car. It's a daily driver. 17 miles to work, and 17 miles back. Just want a reliable vehicle with no extra thrills, but long life.

Looking for advice on purchase of 120A, 90A, replacing other items along with this job of replacing the alternator. Any makes / models of alternators better than the others? Thinking of Bosch or Valeo.
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
First, the A/C compressor is just frewheeling with the clutch disengaged. I would let it be.

Second, your car needs a 120A alternator because it has coolant glow plugs that create a power draw. Automatic trans TDIs didn't have the coolant plugs and had 90A alternators. 90A alternators aren't readily available in the parts market that I know of. Most people are partial to Bosch remanufactured alternators. I like Valeo, too.

Make sure the alternator you buy includes a new clutched pulley. And before you take things apart, look at the serpentine belt tensioner with the engine idling. If the pulley is bouncing then replace the tensioner, or at least the shock absorber on the tensioner.
 

Dannyboy

Veteran Member
Joined
May 25, 2013
Location
Mb
TDI
2014
Stay to bosch and valeo, dont be tempted by cheaper alternatives, you'll regret it later. I just pulled the alternator out of my 2010 golf and it was getting a little noisy until it failed during a regen and literally just made it home just before turning the steering wheel stalled out the engine. Previous owner put some cheapo in there, some of the windings had turned dark blue and I could smell it after I got home.
Usually sparks are bad sign.
 

jokila

Vendor
Joined
Dec 3, 2004
Location
Houston, Texas
TDI
2003 Jetta GLS, Manual
My original alternator started making a noise at about 325K miles. It ended up being the shaft bearings. Otherwise, it worked fine.

I found a local seller on Craigslist who pulled a 120amp one from an Audi. Has worked fine for 150k miles so far.
 

Lightflyer1

Top Post Dawg
Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
Turn that AC on once in a while as well. They don't like not being used for extended periods of time. Defrost runs it as well.
 

Mozambiquer

Vendor , w/Business number
Joined
Mar 21, 2015
Location
Versailles Missouri
TDI
1998 VW Jetta TDI. 1982 VW Rabbit pickup, 2001 VW Jetta TDI
As others have said, stay with Bosch or Valeo. With the Sparks in there, i would probably guess that the small back bearing is gone and is allowing the rotor to contact the windings, which will throw some sparks. Idparts.com has good new alternators for cheaper than what I can sell them for, I rebuild them, but if it's too far gone, it's not worth rebuilding.
 

westenburgdan

New member
Joined
Jan 20, 2020
Location
Michigan
TDI
2002 VW Golf
First, the A/C compressor is just frewheeling with the clutch disengaged. I would let it be.

Second, your car needs a 120A alternator because it has coolant glow plugs that create a power draw. Automatic trans TDIs didn't have the coolant plugs and had 90A alternators. 90A alternators aren't readily available in the parts market that I know of. Most people are partial to Bosch remanufactured alternators. I like Valeo, too.

Make sure the alternator you buy includes a new clutched pulley. And before you take things apart, look at the serpentine belt tensioner with the engine idling. If the pulley is bouncing then replace the tensioner, or at least the shock absorber on the tensioner.
Checked out IDparts. Got tensioner kit since I’m right there removing everything. New Valeo 120 A on the way too.

Will let you know after install is complete the week of sept 12th how things shakes out.
 

westenburgdan

New member
Joined
Jan 20, 2020
Location
Michigan
TDI
2002 VW Golf
Checked out IDparts. Got tensioner kit since I’m right there removing everything. New Valeo 120 A on the way too.



Will let you know after install is complete the week of sept 12th how things shakes out.
So, got the new Valeo 120A alternator in, serpentine belt changed, new belt tensioner in, and idler wheel replaced under the alternator. Purring like a kitten again. Thanks for the tips. Gotta say, there’s not much room in there to work!

with reading some of the posts about the belt tensioner exploding, I’m glad that is changed now at 180,000 miles on the golf!
 

westenburgdan

New member
Joined
Jan 20, 2020
Location
Michigan
TDI
2002 VW Golf
As others have said, stay with Bosch or Valeo. With the Sparks in there, i would probably guess that the small back bearing is gone and is allowing the rotor to contact the windings, which will throw some sparks. Idparts.com has good new alternators for cheaper than what I can sell them for, I rebuild them, but if it's too far gone, it's not worth rebuilding.
If you want my old alternator, you can have it.
 
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