Power Steering Pump/Tensioner

[STONEWALL]

I have an Audi A4 1.9 Tdi Sport 51 Plate, 72,000 Mls.
I developed a noise, that sounded like the power steering pump on it's last legs. On full lock in both directions, the rumble and vibration became worse.
Yesterday, I replaced the pump with a geniune one (new).
There has been a marked improvement, but not a total one. In fact, when I put it on full lock now, it developes a noise, similar to metal catching on metal, when spinning. (rotor blade catching, type of noise)
The drive belt tensioner, is also bobbing about quite a bit, on it,s spring and some of the problem could well lie within that joker. That will be replaced today.
Anyone had similar probs ?
If it is not that, I am at a total loss.
I must say, that I have used a long screwdriver, to listen to both the new pump and the alternator, by putting the end on the item and listening to them, with my ear on the handle, both appear to be turbine smooth.
I am unable to do the same with the tensioner pulley, as I am likely to end up with the screwdriver handle, buried in to my skull or the crewdriver, wrapped around the drive belt, due to it moving about.
Watch this space, update later tonight.

[STONEWALL]

It was the alternator pulley, that also acts as a clutch for the drive belt. It has cured the problem completely. It is a fairly simple task, but for one problem, removing the pulley from the alternator, you will need a special tool. In fact, I had to take it to my local independent alternator supplier, for him to remove the old and put on the new, cost £20. He told me, that any problems with A4 and A6 drive belts, it is normally the alternator clutch pulley, that has seized. A common fault of which he sees many. He suggests the periodic changing of this pulley, every 60 to 70 thousand miles. Seems like good advice.
It has got to be said, that the noise that is created by this pulley, is not that identifiable as coming from the alternator, and thats why I changed the damned P/S pump. Never mind!