# Power Steering Pump Whining in Cold Temps



## GLS-S4 (Jun 6, 2005)

'02 A6 3.0L with 85K KMs.
Pump started whining in colder temps as winter sets in. Steering wheel still feels OK and drivability is so far so good.
Drained all G2000 at lower cooler hose including rack and replaced with G4000 and ran it for a few days, then flushed system again including rack and refilled with new G4000 ensuring no air entered pump during fill. Flush job went well... but same noise still present.
Whining on accel, turning, and just before stopping, otherwise fairly quiet while cruising.
Appears the 3.0L power steering pump is a one of a kind and no reman available yet / no rebuild kits. Dealer wants ALOT for the part!
Any suggestions or similar stories?


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## Slimjimmn (Apr 8, 2006)

*Re: Power Steering Pump Whining in Cold Temps (GLS-S4)*

from what I remember the pump for the 3.0L is the same as the pump for the 2.8L, the parts matched up in the etka system at the dealer. not 100% sure though, vw sometimes puts a the same part on another car but lables it in the parts system as a different part and raises the price. I found that with the breather system hoses for 1.8t engines.


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## GLS-S4 (Jun 6, 2005)

*Re: Power Steering Pump Whining in Cold Temps (Slimjimmn)*

Thanks for the info!
Update - Still wrestling with the whining PS Pump in colder temps.
Some research indicates the noise is an air bubble trapped in the center of the centrifugal pump causing cavitation. After warming up car and checking fluid level was exactly on full mark, I parked and rev'd 4K RPMs constant for 1 minute and then drove again... lo and behold the whining was *almost* gone.
After 2 weeks driving the whining slowly but surely returned. Checked reservoir fluid level again and found it went up 1/2"... WTF!?!
Close inspection revealed ever so slight PS fluid seepage at the pump upper rubber hose band clamp. I recrimped it, washed area clean and am observing to see if fuild sweat returns... speculating that tiny amounts of air may be getting sucked into the pump under some operating conditions.


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## GLS-S4 (Jun 6, 2005)

Update:
After re-crimping upper PSP hose band clamp followed by revving 4K RPM for one minute and then driving for a week... fluid level went down 3/4" when cold and whining is occasionally very slight and mostly gone now. Still speculating air was getting into system and now it is not after the band clamp re-crimp.
Topped up PS Fluid today to factory spec full mark when cold, expecting up to 1cm over full mark reading when fluid level is checked at operating temp as per Bentley.
It was so much fun playing with PS fluid flushes that I also flushed and replaced PS Fluid including rack twice in the daily driver S4 with no problems at all. The rule is to not allow PSP to suck in ANY air while refilling system.
Note original G2000 is brown color and has been superceeded by G4000 which is deep green color. Flushing twice has ensured no fluid discoloration from mixing old with new... worth the $20 to me.
Plan on replacing PS Fluid every ~50K Miles / 80K KMs.


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## Specktater (May 16, 2002)

*Re: Power Steering Pump Whining in Cold Temps (GLS-S4)*

I've got 61k miles on mine (6-spd) with the same symptoms. Shop found a crack in the fluid hose and the fluid was both the color of Coca-Cola and very bubbly. Replaced the hose, flushed and refilled with new fluid and noise persists -- at low speeds, low RPMS and especially in cold.
Noise and vibration seem tied to 1200-1500 rpm range but most noticeable when turning. Audi TSBs haven't found a cause (or cure) but it seems to be common, according to techs I've consulted.
My car lives outside in winter, could just be a cold-weather thing until car warms up.


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## GLS-S4 (Jun 6, 2005)

*Re: Power Steering Pump Whining in Cold Temps (Specktater)*

I'm rambling a bit but I spent way too much time chasing this problem so...

_Quote, originally posted by *Specktater* »_could just be a cold-weather thing until car warms up.

Don't let anyone convince you that cavitation is normal. It's hard on the pump and can lead to premature failure.
The foamy fluid is a bad sign too. I've seen enough air trapped in the system that an engine off fluid check will indicate normal level, yet idling engine fluid level check reveals airated fluid that does not even cover the bottom of the reservoir. This deceiving low fluid state will create constant foamy fluid and noise.
The A6 3.0 made PSP cavitation noise for the first time after a -35C cold spell last winter and the noise lasted for days, without doing any service work the noise was completely gone above freezing temps for the whole summer, then PSP started cavitating again below freezing temps this winter. Despite recent PS fluid flushes, fluid level increased (air getting into system and displacing fluid) along with cavitation noise that did not go away until seeping band clamp was re-crimped... thank goodness for a simple fix. The PS system has since been absolutely noiseless under all winter operating conditions, fluid level remains constant and no air bubbles observed in idling fluid since the band clamp re-crimp.
The most relevant theory is that the PS fluid is thicker in colder temps and a weak clamp / hose connection (esp on low pressure side) can allow air to get sucked in and at the same time not cause an obvious fluid leak making troubleshooting difficult.








The minor seepage band clamp now recrimped and cleaned








You'd be suprised how dirty and black the emptied reservoir was!
Anyone know if the screen can be removed for cleaning?
Using needle nose pliers I was able to unseat it but I could not get it out of the reservoir.











_Modified by GLS-S4 at 12:02 PM 12-30-2008_


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## Specktater (May 16, 2002)

*Re: Power Steering Pump Whining in Cold Temps (GLS-S4)*

Thanks for both the SHOW and the TELL. After a few days of up-and-down temps the noise persists even in warmish (+32 degree) weather. Noise and vibration seems more connected to the RPMs so there may also be more to this story.
-David


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## kevin1533 (Mar 2, 2009)

I had the same problem last winter when the weather was below 20F. Car whined and shook, scared me enough that I stopped the car a block away from my house.
I read somewhere that this occurs b/c of shrinkage of the power steering fluid in the cold. So I added a bit above the full and that seemed to have solved the problem for me at least.


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## The Engineer (Oct 9, 2006)

*Re: Power Steering Pump Whining in Cold Temps (GLS-S4)*

Thanks for the writeup.
I'm having exactly the same issue and had no luck other to find "my pump whines as well" turn up during my searches.








Actually had this for 3 years now - noise getting worse each year only in the winter time with temperatures below +3C.
This year I almost thought my PSP would explode.
It seems from your explanation (which makes sense) I need to fix it - cavitation will eventually break the pump otherwise.(I thought I could just sit it out)
As to the procedure of draining and refilling - I did not find a writeup with pictures anywhere.
Is where your pictures show the loose crimp connection that you re-tightened the right place to drain the fluid ? I assume it's shot from underneath facing up !?
To save me the trouble to crawl underneath and search - I assume it's underneath easily accessible or do I need to disassemble half of the underbody ?
A little walk through would be greatly appreciated








Thanks
FD


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## GLS-S4 (Jun 6, 2005)

*Re: Power Steering Pump Whining in Cold Temps (The Engineer)*

You may not have to replace fluid to fix the cavitation issue, you really just need to stop air from entering the system. Audi says once system is sealed properly, any remnant air bubbles will work themselves out of the PS system within 1K KMs of regular driving.
The pics above are topside engine bay of PS Pump. I've realized that unbolting the PSP to make room for other work can strain the hose connections so recommend clamp re-crimps. First step in troubleshooting cavitation is inspect for leaks and tighten all PS clamps.
You may want to inspect the Tie Rod end boots to see if fluid is accumulating, meaning rack is leaking and possibly letting air in that way.
What I did to completely replace PS fluid: Purchase 1L G4000. Disconnect lower PS Hose underneath engine and drain system. Lift front end and turn wheels lock to lock several times to drain rack fluid as well. I installed a flex rubber hose on the open end of hard line and put both open ends in a jar while air blow gun pressurizing the reservoir to force nearly all old fluid out of ps cooler low spots. Close system and fill as per Bentley. Do not let ANY air to enter system while re-filling, meaning do not empty the reservoir or else an air bubble will likely trap in center of pump and immediately cavitate / displace fluid and setup for false fluid level reading. Note PS Pump will not move any fluid until engine is actually running. First reservoir fill needs engine on idle for ONLY 2 seconds, then fill again and run engine 2 seconds, top up fluid and with front wheels off ground turn lock to lock 10 times, then set fluid level to spec.
The two PS hoses feeding the PS cooler are beside engine oil filter, side by side and visible under driver side below PS reservoir. Disconnect lower PS hose to drain system as it is the lowest point.
Hope that helps http://****************.com/smile/emthup.gif 










_Modified by GLS-S4 at 1:03 PM 3-16-2009_


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