Quiet grinding noise and small metal flakes

Russnut

Veteran Member
Joined
Aug 15, 2007
Location
Layton Utah
TDI
03' Jetta TDi
I can normally diagnose most anything on the car, but this one I'm not quiet sure of. There's a faint grinding noise coming from the passenger side of the engine compartment. And with that, there are some very fine metal flakes flipping up off the accessory belt. The car seems to be running just fine, but metal flakes are never good.

Car details: 2003 Jetta, 210,000 miles, timing belt/waterpump/andallthatstuff done @ 180k by Kerma.

The noise is louder if you get lower to the ground. It does not sound like there's anything wrong with the IP. My guess is it's the alternator about ready to explode. Possibly bearings in it? Any other guesses? Thanks for any input.
 

Russnut

Veteran Member
Joined
Aug 15, 2007
Location
Layton Utah
TDI
03' Jetta TDi
The alternator is one of the few things that hasn't been taken off before. Is there a difference in the genuine and the german pulley? The alternator is still working just fine btw.
 
Last edited:

whitedog

Veteran Member
Joined
Jul 12, 2004
Location
Bend, Oregon
TDI
2004 Jetta that I fill by myself
Yes. It is a one way clutch and they fail quite often, especially on the 2003. You can replace the pully on the car if you have the right tool adapted to the job. otherwise, you need to pull it out.
 

Russnut

Veteran Member
Joined
Aug 15, 2007
Location
Layton Utah
TDI
03' Jetta TDi
How long does one suppose it'll last before something unhappy happens? I will order a pulley tonight.
 

whitedog

Veteran Member
Joined
Jul 12, 2004
Location
Bend, Oregon
TDI
2004 Jetta that I fill by myself
Order a tool as well since you will need that to change the pully. There are posts here about changing it.
 

Powder Hound

Top Post Dawg
Joined
Oct 25, 1999
Location
Under a Bridge, Crestview, FL, USA
TDI
'00 Golf 4dr White 5sp, '02 Jettachero 5sp, Wife's '03 NB Platinum Gray auto(!)
The alternator has an overrun bearing buried in the pulley. It has been described as a "clutch" or rachet action, and basically it allows the alternator to freely spin in 1 direction and be driven in the other. Alternately said, the alternator is driven in one direction, but if the engine speed slows suddenly, the alternator can keep spinning faster if it happens to be unloaded.

These bearings have been known to fail, and apparently there is nothing to be done.

Sometime some enterprising soul is going to figure out how to refurbish these pulleys and have a lot of business.

Either metalman or metalnerd makes a toolset needed to r & r the pulley. There's a couple of suppliers (check the vendor section in the for sale threads) that also sell just the pulley.
 

Russnut

Veteran Member
Joined
Aug 15, 2007
Location
Layton Utah
TDI
03' Jetta TDi
one more question. Is there a clutched pulley that is sold separately? I seem to only find the "free wheeling" one. Or does Impex not have the clutched one by itself?
 
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