Help! My diesel is doing strange things!

[blackcat 0]

I have a mk3 turbo diesel golf and it is doing very strange things....

 

For a few months now the alternator belt has been squealing when started from cold and I've been meaning to get round to changing it for ages but....

 

last night when I was driving home, everytime I hit 2500 revs, the rev needle dropped to zero and the battery light flickered, then it would right itself and the rev counter would go back to normal.

 

Now this morning, the rev counter seems to not work at all, it is staying on zero and the battery light is on and the oil and water light flash, like when its stalled.

 

The car is still drivable and I can't feel any difference in the car, it still revs and accelerates normally,, it just doesn't show on the rev counter!? The only difference is now the belt is not squealing.

 

Does anyone know what is going on? Is something wrong with the belt and it's not charging the alternator properly? I have checked and the belt is still going round.

[vwdeviant 0]

Is it Haunted? (It's that time of year you know)

 

Sounds like some form of Errror code.. maybe? Any-one close by got VAGCOM?

[coolrado 0]

can you check the voltage at the battery with the engine running and with the engine off, it should be around 12v with the engine off and around 13.5-14v with the engine running if there is no change, the alternator or just the brush pack on the alternator could be worn out, the alternator warning light used to come when revved on my caddy diesel when the brushes went, but im not sure any other lights came on.

 

if the alternator is not charging the battery be carefull doing any night time journeys, as its a diesel it will probably carry on running but you wont have any lights when the battery goes flat.

[blackcat 0]

Is it Haunted? (It's that time of year you know)

 

:lol: lol, probably. My car seems to have a life of its own most of the time anyway.

 

Thanks for the suggestion coolrado, I'll check the battery voltage tonight. Is there anyway to find out if it is the alternator/brush pack for sure?

[Toad 0]

Has the belt snapped???

[blackcat 0]

nope, still going round.

[coolrado 0]

Is it Haunted? (It's that time of year you know)

 

:lol: lol, probably. My car seems to have a life of its own most of the time anyway.

 

Thanks for the suggestion coolrado, I'll check the battery voltage tonight. Is there anyway to find out if it is the alternator/brush pack for sure?

yeah if you remove the brush/regulator pack and the brushes only stick out by about 3mm they will be worn out, you only need to remove 2 screws to remove the brush/regulator pack which will look something like this.....

[blackcat 0]

ok, ta very much for the pic, I'll attempt to have a look this evening !!

[Crasher 3]

The alternator also drives the rev counter on the AAZ Umwelt TD engine which is what I imagine you have so if the light is on and the rev counter doesn

[coolrado 0]

ah, so the brush/regulator pack will probably be nothing like that then.

[Crasher 3]

Nothing like what?

[blackcat 0]

The alternator also drives the rev counter on the AAZ Umwelt TD engine which is what I imagine you have so if the light is on and the rev counter doesn

[Supercharged 2]

The MK3 Bosch and Valeo alternators have the fan inside the casing and the brushpack is usually under the black plastic cover on the right...

 

I assume you can take the cover off with it on the car - usually held on by 3-5 M5 (8mm) nuts... the pack is then underneath with another black bit of plastic covering the brushes... not sure if the pack itself coukld cause the above tho, Steve???

[blackcat 0]

Would the mk3 2l 8v gti have the same alternator?

 

(If so, I could swap the one in my car for the one from my other half's gti to see if it was the alternator)

[Supercharged 2]

Worth a look but I think the TDI one will be bigger (higher output)

[blackcat 0]

ok, so we took the alternator off and took the brushes out, then we put it all back together and put it back with a new belt and all is fine! Yay :D

 

Not sure how long it'll last because the brushes looked they could do with replacing so now I've just got to find somewhere to get some brushes from - all the places I've spoke to seem to want to sell me a whole alternator :?

 

But, for now, it's working, Thanks guys :D

[Supercharged 2]

Hi Angela, you can get the brushes from an autoelctrician for pennies but best let them solder them in as it's an arse...

 

The other option is to replace the diode / brush pack, it may have a 10 digit Bosch number on it, if you look on the Bosch website you'll find your local dealer...