If the sound is actually the water pump rather than the
tensioner (hard to tell the difference) it would make sort of a
buzzing sound.

After R&R belt, pump and tensioner on my '91 100Q 5cyl last
December it took to making a whining noise at idle when cold but
quit when warmed a bit.

The belt tension is checked like you say with the 90 degree
twist but even the it is a mater of how hard it is to twist.
Another way I test it to look for about 3/8 to 1/2 inch of flex
in the belt between the water pump and the cam pulley.

The bearings in the tenwioner are sealed and do not need
greasing.

Tony
'91 100Q 5spd

PSH wrote:
>
> I just finished replacing a water pump, timing belt and tensioner
> roller on a 4 cylinder 1990 Audi 80. All went well but after less than
> 100 miles the tensioner roller is making a rubbing noise. It is quiet
> when first started but once its warm it makes noise. Do I need to
> lubricate the roller? I paid $50.00 for it from NAPA auto parts so it
> was not a cheap one. Should the roller be lubed with heavy 90 wt oil
> or grease? The belt is not to tight I can turn it 90 degrees no
> problem. I hope I don't have to tear this ?><*%&$ thing apart again!
> Thanks for any reply!

 

Tony Johnson wrote:
> If the sound is actually the water pump rather than the
> tensioner (hard to tell the difference) it would make sort of a
> buzzing sound.
>
> After R&R belt, pump and tensioner on my '91 100Q 5cyl last
> December it took to making a whining noise at idle when cold but
> quit when warmed a bit.
>
> The belt tension is checked like you say with the 90 degree
> twist but even the it is a mater of how hard it is to twist.
> Another way I test it to look for about 3/8 to 1/2 inch of flex
> in the belt between the water pump and the cam pulley.
>
> The bearings in the tenwioner are sealed and do not need
> greasing.
>
> Tony
> '91 100Q 5spd
>
> PSH wrote:
>
>>I just finished replacing a water pump, timing belt and tensioner
>>roller on a 4 cylinder 1990 Audi 80. All went well but after less than
>>100 miles the tensioner roller is making a rubbing noise. It is quiet
>>when first started but once its warm it makes noise. Do I need to
>>lubricate the roller? I paid $50.00 for it from NAPA auto parts so it
>>was not a cheap one. Should the roller be lubed with heavy 90 wt oil
>>or grease? The belt is not to tight I can turn it 90 degrees no
>>problem. I hope I don't have to tear this ?><*%&$ thing apart again!
>>Thanks for any reply!
I used the 90 deg twist test when I did my Golf's belt, and got it too
tight. Try loosening the belt a little (only a tiny amount!) and see if
it improves.

 

You guys were right. I had the belt to tight. Loosened it to have an
easy 3/8 inch deflection and the roller noise is gone. This was the
first belt I have replaced. I have done timing chains but you don't
adjust them. Now I know how to replace timing belts the correct way.
Thank you for the help.