Audi A6 C5 1.9tdi electrical/ alternator issues

[Preze]

Hello

I have used this forum several times to help fault diagnose on my 2003 A6 avant

However I know have an issue I can't seem to find the answer to.

My car began to lose voltage from alternor whilst driving from cold or through wet puddles, the belt slip got worse to the point that I would lose power steering and be running off of just battery power for minutes at a time. So I went to find a fix.

First off I tested to see if the alternator pulley was serviceable, which it was, spinning in one direction when movement was pervented, stopped solid in the other. I then tried to spray some water on the belt when running, which gave slip and a voltage drop read from the dials. I went about changing the drive belt, which fixed it for one day but now it's back worse than ever. Strangely the voltage now increases when water is sprayed onto the belt and it only sometimes actually makes a screech. Any ideas?

 

[thawatchai2510]

Mean belt was slip.
1.choke or roller of belt was stuck.
2.Belt was too stretch.
To solve.
1. Spary WD40 at choke or the core of roller (no1) and shake it must move as spring with hex l tool (in pic.) .
2.Tensioner or Belt chang.

 

[Audi90aby]

I dont kid don’t know if this will help but iv just been going through the same with my a6 c5. When it was cold it wouldn’t charge the battery so that meant it was going flat all the time drive through a puddle would get even worse until it got worm. What I did was put a different altonator on it and that has sorted the problem so even if it looks fine it may not be. Hope this helps

 

[Preze]

Hi guys,
To update you, in the end I just decided to strip the front off to attempt to discover the issue, I ended up finding my tensioner was shot, one eye end had completely sheared off and the other was worn into a slot shape rather than a tight fit bearing I checked all pulleys and found them to be functioning correctly, I.e. minimal play and free turning. Changed the tensioner, replaced the tired old battery, put it back together and it was sorted. Didn't take too long either, maybe three hours including checking reference material.

 

[thawatchai2510]

Hi guys,
To update you, in the end I just decided to strip the front off to attempt to discover the issue, I ended up finding my tensioner was shot, one eye end had completely sheared off and the other was worn into a slot shape rather than a tight fit bearing I checked all pulleys and found them to be functioning correctly, I.e. minimal play and free turning. Changed the tensioner, replaced the tired old battery, put it back together and it was sorted. Didn't take too long either, maybe three hours including checking reference material.

GOOD FIT GOOD DRIVE
SHERE