Power Steering Problems!!!!!

[nobbya]

I have an Audi 80 Sport 2.0 1995. In February I noticed a hissing sound tranlating itself through the dash and the steering column. The hiss would not appear at first but would gradually get louder as the car warmed up. The hiss only occurs when the steering is not being turned (either left or right) and when returning the steering from lock back to a central position.

I contacted audi who took a look and said the steering rack was at fault. Audi's price for a replacement was ridiculous so I purchased a rack elsewhere and had it fitted. The problem was still present. Next I was told it was the pump so after saving some money I purchased a new pump.

Before I could fit the pump the steering failed and so I got to work presuming the pump had failed and promptly fitted the new one. The steering failed again and dumped all of the hydraulic fluid into the footwell behind the pedals.

The rack and pump were sent off to be tested (4 Weeks!!!!) and it was found that the pump was fine and after the repair on the seal of the rack was carried out that this was also ok.

However I still have the same problem that occurred 7 months ago.

Can anyone give me a clue as to the origins of this hissing noise?

Everytime I ask for advice and help from mechanics they scratch their heads like Stan Laurel and the whole thing is turning into a farce as well as costing me more money.

 

[nobbya]

The car only lost hydraulic fluid when the first replacement racks pinion seal inverted. no leaks from it otherwise since the problem started and no leaks from the pump.

The noise has never stopped from the time it first started to occur in february.

 

[audi5e]

How does you car run? Is the engine smooth?

Do any of the coolant hoses pass close to or touch the steering arms? or any of the vacuum hoses?

 

[nobbya]

I have no problems with the engine performance. Even though the noise appears to come from the power steering I also have no loss in steering response. Infact now that a new pump and rack are on the steering is better than when I bought the car in 1998. There does appear to be a slight drone when accelerating and is most prominent at 3000 rpm. This occurs all the way through the rev range and pitches with the engine tone. It is definitely not gearbox as it does this just when revving. Could that be related? It is difficult to pinpoint its location from outside but inside it appears to come from the passenger side of the engine bay.

This is where the power steering pump and water pump are located connecting to the drive shaft with the starter motor sitting on top of the engine on this side.

It is difficult to see every section of the hoses without removing engine components but the steering arms appear to be clear of obstruction. Everything seems to be in place.

 

[audi5e]

I would normally put a hissing sound down to either a coolant hose, but in your case you are not losing coolant, or I would say a vacuum leak. At idle, if you turn the steering then you put a load of the engine (which has to overcome the pump working), this in turn will make your injection system compensate and up the air/fuel intake to keep the idle from dropping. If there is a vacuum leak somewhere you would be able to hear it increase at this point. You may find there is a very slight hole or tear in one of the hoses and this is actually causing the noise? Of course I am just guessing without actually hearing the car myself.
It makes sense with the age of the car too, that a pipe is probably fatigued.

Get yourself a hollow tube, then run the engine and hold one end of the pipe to your ear and run the other end close to where you think the noise originates, you should be able to pin point it. If you can get someone to gradually increase the engine speed so the noise becomes more noticeable.

Another thing it could be is an air leak in the power steering? slight enough that there is no noticeable effect on steering but enough to make a noise. Do you get any air bubbles in the steering fluid?

 

[nobbya]

The hissing sound does not increase when when the steering is turned. Infact it takes very little to make the hiss stop, only a slight turn either left or right to put a small amount of load onto the steering will stop the hiss altogether.

One of the first things that I checked for was foaming in the fluid reservoir incase air was getting into the system but the fluid is ok.

I tried the hollow tube technique and it definitely seems to be coming from the rack or the noise is somehow manifesting itself through the rack as a result of something else.

With the bonnet open you don't need a tube to pinpoint the location as the rack is exposed to view seated directly above and to the right (of the car) of the gearbox. Simply leaning over the engine will allow you to hear it. Increasing the revs does not affect the hiss only the drone.

The best place to hear the problem is behind the steering wheel with the doors closed. The hiss translates itself into the dash (drivers side only) and up the steering column.

With 3 racks been on the car this year and 2 pumps it's plain to see why people are getting confused.

Could the problem be a result of reduced pressure instead caused by wear and tear in the components linked to the pump through the belts (which are not worn)?

If I squeeze the return pipe to the reservoir from the rack to hold the fluid back the hiss also disappears.

 

[audi5e]

Have the pipes from/to the rack ever been changed? I wonder if one of them is possibly an incorrect diameter on the inside? Maybe your squeezing action closed the diameter to a more correct size? Then your question on pressure loss would also make sense.

 

[foolish3uk]

if memory serves me correct they have a one way valve in the return pipe obiously to stop fluid from trying to go the wrong way, i would recommed replacing this pipe as you have said, if you squeeze it,it stops,

good luck hunting!

 

[nobbya]

I think I may die if this is the problem. Especially since I've forked out in excess of £600 to try and solve this.

I can't imagine that a replacment return pipe will cost much though.

In the mean time I've booked the car into my local Audi dealer for a diagnosis and I will take these comments along together with a report that I obtained on the rack and pump tests and show them to the mechanics. Hopefully this will solve it!!!!!

Thanks for the help so far. I will repost a notice when things have been completed for an update just incase someone else has a similar problem. I would hate anyone to have to go through so much trouble, time wasting and most of all expense for the sake of a valve.

In the mean time fingers crossed.

 

[audi5e]

crossed.

 

[audi5e]

Definitely go to Audi. You don't want to end up with an inferior PS oil!

 

[imported_carjacker0]

I ended up going to Audi and a litre bottle only cost about £7.50 even though i only needed a a couple of ML..The one thing i did notice is it's a green colour whereas the oil already in the car is clear.Any difference do you think or should i just remove all the oil from resevoir and replace with new stuff??.

 

[nobbya]

Back again.

Just got back from Audi yesterday afternoon. The mechanic first adjusted the belts which was a wrong decision as they squeeled when starting the car then they replaced the hoses. After spending close to £1000 on trying to solve the problem it is finally cured.

The hose which returns back to the reservoir does indeed have a valve in which was the most expensive part (£157).
It was this that had failed.

Now for all my expense I have a completely new power steering sytem fitted to the car which was not required.

If only such expense would add to the value of the car (which it won't!)

It's quite a strange feeling to have the car functioning correctly after so many months. I quite miss the noise (Not!!!!!).

If anyone reads this who experiences a similar problem please replace the hoses first before relying on opinion about the rack and pump. THE NOISE WAS IN THE RACK BUT ONLY AS A RESULT OF THE VALVE IN THE HOSE.

Thanks guys for the help it's been invaluable in solving the problem. If I experience any more problems I will come here for advice. It's great to find people who are passionate about their cars like myself as I love my Audi, even if it is a getting on a bit.

Thanks again.

 

[audi5e]

excellent!!!

 

[bibbleb]

WOW, i am having this exact same problem with my A4. Thanks so much for the detailed coverage on fixing this problem, sorry you had to spend so much money, likely you just saved me a bunch though....thanks