Power Steering

**Scottyjohn** · 13-12-2007,10:49 AM

Hi all,
Gave my car to a friend on a mercy mission last week and when I got it back its making a hell of a noise. At idle, there is a rumble / squeak from the front of the engine bay. This disappears when raised above idle. When driving the car, at low speed, and turning with fair lock, the car squeaks and judders through the wheel as if the front wheels are not aligned and pushing against one another. If I keep the revs up when turning tightly it drives fine. I checked and the power steering fluid was below the minimum and I hoped that this was the issue but have topped up with audi fluid today and hasnt made a difference.

Im hoping it isnt going to need a rack or a pump? Any ideas on the possible cause?

**RickT** · 13-12-2007,03:50 PM

make sure its not a lose engine mount... these tend to rattle on idle and fade a little bit when you apply power,

If not.. ensure all is aligned correctly... Ensure your mate did not hit anything like a large pot hole..

Rick

**rhencullen1989** · 13-12-2007,11:37 PM

It may be a shot in the dark but is the tensioner on the auxillary belt ok, you don't say what year or model it is. A friend of mine has a 2002 passat and the auxillary belt is damped by a tensioner that is sprung loaded and also oil damped. His was knackered and was making a horrible rumbling noise on low revs that would disappear as he revved the engine. If you are experiencing a squeelin noise on full lock, that points to a belt tension problem.

**Scottyjohn** · 16-12-2007,11:48 PM

Hi guys,
thanks for the replies! I had a look at the tensioner and it seemed to be oscillating a fair bit and I presumed that this tensioner should more or less be still when running? So I replaced full tensioner and belt and it appeared initially to fix the problem, certainly the really bad rumble at low revs and squeeking / judder through the steering when stationary and turnin the wheel.
However tonight it appears to be a bit rumbly again and also squeaked a few times when parking, with the same judder in the steering when parking. Im assuming now that there must be another cause of the issue that perhaps a worn tensioner made worse. Can anyone tell me how much their tensioner seems to move when idling? I checked all the pulley wheels for play and all seemed tight. I dont know what to look at next. Perhaps a power steering pump?

Any advice would be of great help. Not looking forward to removing bumper again and loosening front panel again!

**Scottyjohn** · 16-12-2007,11:50 PM

Oh sorry Rhencollin but the model and year is on my signature, 2002 a4 TDI Avant 130 SE

**mastertech** · 16-12-2007,11:56 PM

This is caused by the One way pulley on the alternator seizing up .It needs to be replaced.--Cost about £40 + fitting. Common problem with TDI

**Scottyjohn** · 17-12-2007,12:05 AM

Cheers mate! Is it the whole alternator or just a component? So there is a mechanism which only allows the alternator to turn one way?

**Scottyjohn** · 17-12-2007,05:56 PM

Hi all,
Can anyone advise if this is a seperate part on the alternator which can be replaced or is it an alternator swap?

**mastertech** · 17-12-2007,10:23 PM

No- you just need to replace the pulley--But a special splined tool is required.
The pulley is approx £40+VAT. The alternator needs to be removed and to do this the viscous cooling fan needs to be unbolted from its bearing--Advice a dealer or specialist.

the pulley only drives the alternator in one direction, in the other direction it slips