Noisy power steering, elementary questions

[Jimmy2007]

Hi everyone, Audi A6 C6 4F 2008 3.0l quattro, all of a sudden, after a cold night i got this little noise when stationary and moving the wheels.
It's the same noise you get when on full lock, but this is present even by slightly turning the wheels.
Also the revs go down a tiny touch (but noticeably) when doing that.
I had a look at the reservoir and it was on min, so i topped it up and followed the bleed procedure.
Much better, but noise still there.
So reading about this problem, it appears that the hoses' clamps are not the best and can let air in the system.
Now, i can see the 2 hoses going into the reservoir and the clamps (totally dry) but, and excuse me for the silly question, where's the PS pump?
A picture would be great.

Also, when I bought the car a couple of years ago I enquired about cam belt change and I was told my car hasn't got one, but a chain and having only 50k miles I shouldn't do anything to it.
Could anyone confirm this please?

Thanks

 

[abmat]

AFAIK chain at the back, belt at the front to drive fuel pump.

 

[Jimmy2007]

Anyone willing to chip in regarding the noise when turning wheels please?

 

[abmat]

Shot in the dark, could be the pump failing.

 

[Jimmy2007]

Thanks, is there a way to test the pump before throwing money away?
Also, any guidance on how to replace the hose clamps?
From the top it looks like the pump is at the bottom passenger side, correct?

 

[abmat]

I’m afraid I’m out on this one. Only offering possible causes.

perhaps @B5NUT might be able to help. He’s done quite a bit on the A6

 

[B5NUT]

When was the last time the fluid was ever changed?

 

[Jimmy2007]

Never changed, just clocked 50k and planned to do at next service.
Do you reckon it needs changing urgently?

 

[B5NUT]

Before you chuck good money at a pump I would make sure the PAS fluid is ok first, the car may only have 50K miles but the fluid is almost 14 years old, and most likely well passed it's best.

It's any easy change as well. Drain the reservoir and disconnect the return pipe and push that into a container. Block off the return on the reservoir and fill with new fluid. Get some to start the engine and allow the pump to to fill the container with the old fluid, keeping the reservoir topped up. Once the you can see clean fluid coming through then stop the engine and refit the pipe, then top up the fluid.

I would also check for leaks around the rack as the missing fluid has gone somewhere.

 

[Jimmy2007]

Will do, thanks.
One thing I'm unclear, once i start the engine, do i need to turn wheels or will it just pump fluid on its own?
Also, which one is the return pipe, top or bottom?

 

[B5NUT]

You could do it won't cause any harm. The main point is not to let the reservoir run dry as you will end up with a lot of air in the system which will make the pump even more noisy!

 

[Jimmy2007]

Ok, thanks.
I suppose the return pipe is the one at bottom with the fishnet sleeve.
Correct?
My reservoir looks like the on in the picture attached.
Is there a way to check for sure which one is the return pipe?
Thanks

 

[B5NUT]

I cannot remember the feed pipe should be going to the pump, the return should be coming from the cooler mounted in front of the radiator.

 

[abmat]

Logic would say the pipe with the smaller bore is the feed as it is at a higher pressure than the return? Or am I talking sh!t£

 

[Jimmy2007]

I cannot remember the feed pipe should be going to the pump, the return should be coming from the cooler mounted in front of the radiator.

Ok, thanks.
I'll check it out and if I can't work it out I take some pictures.
It's very cramped in there.

 

[Jimmy2007]

Accordingly to this scheme the return should be the smaller hose fitted at the top of the reservoir (10).
The bottom larger hose (3) is listed as the feed.
Correct?
I just wanna say thank you for your help.
I really appreciate it.

Please copy and paste all of the following, otherwise it doesn't work.

https://7zap.com/en/catalog/cars/Audi/brand/3/0/Audi A6/Audi A6 (2008 - 2011)/Audi/UThlN2dLaU1hSllPUnpQNHMrNnZNQT09--/6bbffde8b5b8077d2d0a5796da6eea3c:7477da17ddd2975b3a9c557ba32c9f58/manufacturer/4/448422600::422060

 

[B5NUT]

It would make sense the larger dimeter pipe is the feed, You could also disconnect at point 25 in that drawing, it's whatever is easiest to access.

 

[Jimmy2007]

Thanks, I'll see if I can attack this job asap and let you know.
Last question if you don't mind:
The cap on the reservoir says use only G002000 oil.
Is febi 06161 the correct fluid?
I used it in my Passat.
2 litres enough?

Thanks

 

[Jimmy2007]

https://partsfinder.bilsteingroup.com/en/article/febi/06161

This one i mean

 

[B5NUT]

Sorry on the oil front I could not tell you, I get all my fluids from TPS, so it's either the genuine VAG stuff or the VW quantum range. 2 litres would be more than enough to flush the PAS system.

 

[Jimmy2007]

Nice one.
Thanks.

BTW, are you called B5NUT because you like B5s?
My other car is a Passat B5 1.8T 150bhp, I call her "My Lady Beast"

 

[B5NUT]

Yes, and I still have my first B5 I purchased over 20 years ago, which is near the end of it's restoration.

 

[Jimmy2007]

Nice one.
Are you on the ukpassat forum?
I'm there

 

[B5NUT]

It's not a B5 Passat, it's a B5 A4 https://www.audi-sport.net/xf/threads/audi-a4-restoration-rebuild-thread.420769/.

 

[Jimmy2007]

Ah, ok.
I have the B5 of the poor, although I love it.

 

[Jimmy2007]

Hi, sorry for the delay in updating.
For the benefit of someone here i write how it went.
I measured the return pipe diameter which is 16.5 mm because i realised it's too short to go straight in a bottle, there's no much space.
So i had to use an extension pipe about 20cm long.
Here is a £300 special tool directly from audi

I warmed up a piece of hose and pushed a 13 mm socket in it (17mm).

I left it there until cool, then added a jubilee clip.
To block the return hole in the reservoir, here is another special tool directly from Audi...

It's another piece of hose, this one more rigid from an old washing machine inlet pipe, one end blocked with silicone, then jubilee clip to finish.
Now, the first problem is that the reservoir has a net filter not far from the top level of fluid which doesn't look like it can come out unless forced.
I didn't want to break anything, so i sucked as much fluid as i could with this other special tool (this is a bit more pricey at £450 from main dealer)...

Then an old towel under the reservoir, return pipe off, special tool number 2 in and special tool number 1 into the pipe.
Jubilee clips done up not too tight.
The rest is as described above.
I used a 1 litre schweppes bottle which is thin enough to go in a gap under the coolant reservoir which needs to be moved out of the way.
Fill the reservoir and once the assistant starts the car, be ready to pour the fresh coolant quite quickly.
The bottle gets filled in about 20 seconds.
I poured 1.5 litre, although fresh fluid came out after the first litre.
Then when you remove the special tool number 2 to refit the pipe, fluid will drop, so you can use what's left of the 2 bottles to top up once all is fitted again.
Once you start the car, some micro bubbles come up in the reservoir, but after a few seconds all is good.
I turned the wheels a few times full lock, checked level and then for the next couple of days checked level cold and hot.
All perfect.
The pump doesn't make that noise anymore and power steering seems smoother, but maybe it's just my impression.
One thing for sure, the fluid that was there had become dark brown.
It's now a nice vibrant green.
The fluid is £12/bottle from main dealer.
So overall, seems that the problem is sorted.
I hope this helps someone.
Thank you to all who contributed.
Thanks.

 

[Jimmy2007]

For further benefit of some.
Time came to change pas fluid on my passat and both cars' brake fluid.
So I splashed £31 on an extractor pump, aka vacuum pump, having "lost" my old trusted one a few years ago.
So much easier and clean to do all of this.
If you maintain your own car, I strongly recommend one of these.