Ticking from alternator belt after replacement

[NebToast]

I replaced both belts and the tensioner the other day on my 1992 EX GTII, and now the alternator drive belt is making a ticking noise once per revolution. The car was new to me so I'm not sure if it was doing it before but it's definitely got worse. I thought it might have been tension in the belt but I've tightened it and if anything that made it worse. My guess is the water pump, I took the pulley off to change the cam belt.

Is the ticking a symptom of a water pump at the end of its life? I've got one waiting at eurocarparts to replace, otherwise could the belt just be rubbing in one area?

[mark1gls]

How old is your alternator/water pump belt?

To check where the noise is coming from remove the alternator belt and start the car, if the noise has gone it’s that belt etc thats the problem but if you still have the noise it’s from the cambelt.

If noise from cam belt check the covers are not catching the belt.

You can run the engine for long with the belt removed as the water is not turning and the alternator is not charging....

[NebToast]

How old is your alternator/water pump belt?

To check where the noise is coming from remove the alternator belt and start the car, if the noise has gone it’s that belt etc thats the problem but if you still have the noise it’s from the cambelt.

Brand new alternator belt along with the cam belt

[NebToast]

Just replaced the water pump, it didn't fix the ticking. With the belt off there was no noise so it must be the alternator. Are new alternator bearings the answer? If so where can I find them? (Or am I going to have to get hold of a new alternator)

[mark1gls]

How old is the belt? Replace them every 12 months, 950x10 belt if you don’t have air con or power steering.

https://www.eurocarparts.com/ecp/c/Volk ... b16&000108

Next step I would do is check you fitted the water pump pully is flush and it runs true, then check clearance or remove the cover for the cam belt in case the belt or pully is hitting the cover.

When you have removed the belt spin the alternator and listen for rough bearings and feel for play in the shaft.

[james butler]

try running the engine without the alternator belt on just to checkouts not engine related.
if your sure its alternator they can be stripped fairly easily and new bearings installed.
alternatively local moterfactors can do you an exchange one for less than £100 as its 50% of atm https://www.eurocarparts.com/ecp/c/Volk ... a27&000012

[DannyH]

You could try loosening the fan belt the garage loosened mine.

[NebToast]

It's a new alternator belt, the right size. The alternator had a bit of play in the shaft so I'm assuming it's that. It's a Bosch 90A, where can I get hold of new bearings and rebuild kit?

[NebToast]

I've got a couple of spare smaller MK2 polo alternators. Are the parts common across all Bosch alternators from this era? I could swap over the bearings, as I can't find the right repair kit based on the alternator part number 026 903 015 b

[blakey]

Using the two links below, you may be able to do some cross referencing to see what it compatible:

http://www.bosch-automotive-catalog.com ... jvic2h8f35

https://volkswagen.7zap.com/en/rdw/

To be honest, if it is the alternator, as James suggests exchange it at ECP with their current discounts. You may fix the bearing problem only to have electrical issues with it in the future.

Before you do, as it is a 90 A, make sure that is applicable to the Scirocco, if it's not just order it against a later vehicle (Golf etc.)

[mark1gls]

Would 92 cars come with a 90amp alternator?
I thought they came with 65amp alternator and the 90amp updated alternator was a mod to be helpful if running a big amp/sub, sound system, electric windows etc....

[NebToast]

Would 92 cars come with a 90amp alternator?
I thought they came with 65amp alternator and the 90amp updated alternator was a mod to be helpful if running a big amp/sub, sound system, electric windows etc....

Sounds likely actually, there are leccy windows and clearly used to be big subs in the boot.

[NebToast]

I replaced the alternator (either way the bearings were noisy) and... Still ticking! The only thing I can think is that the alternator fan blade things are catching on the timing cover or that the belt I have is a duff unit that is already separating. The old belt won't fit on with the new alternator however, so the new belt must be slightly bigger (old belt size unknown but new belt is 10x850). Having replaced the water pump and alternator I'm no longer afraid to drive it for fear of some big breakdown but the noise is something I'd still like to work out

[mark1gls]

Can you post up some pictures, we might be able to see something...
Strange how the 850x10 belt fits as standard cars had a 950x10 belt?

[NebToast]

So I think I've finally identified the source of the noise, the water pump pulley itself has some rust on the pulley surface and it sounds like the V-belt is rubbing on that every revolution. Do you think it's worth taking it off and sanding it down or just getting a new pulley as an unpainted surface will just rust again?