Hey everyone. I have a 05 A4 Avant Quattro. It’s a TIP with 85,000 miles.
I went through last winter without a problem, but so far this year when the temp drops below 40 degrees, my steering becomes incredibly loud. The PS fluid level is at its max and I still have an issue. The dealer recommended flushing the system, which they did, but that did not seem to help either. I have looked in the PS reservoir shortly after starting and I have found it filled with bubbles. A lot of bubbles. I know air is not good inside a hydraulic system, but I don’t know if this is "normal" for Audi.

So I guess I have 2 questions.
1. Why does the cold weather cause it? (and fluid constriction does not seem to be a valid reason, because the PS level is at its max, even with the car is running)
2. What in the system can be replaced to remedy the noise? (new lines, new filter, new pump, ...?)

 

i dunno but id bleed the system out , to get rid of those bubbles. and then if the sound is still there id try to find out where exactly the sound comes from

 

Hey...check out my bulletin I posted earlier tonight under A4 and under A4 B6. We may be having the same problem. Let me know, because I hadn't checked the ps fluid, but figured the diagnostics would tell me if I was low.

 

haha wow, it just got cold enough in new jersey and i was having the same situation. it seems once the car gets warm enough that the noise goes away.

 

seahawkfan94
Senior Member Join Date: Jun 2005
Location: Vancouver/Portland Area
Posts: 205


Help please!

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I have an '04 3.0 tip ultra-sport, and have noticed off and on a vibration and humming sound from the front-end at low speeds. I first noticed a few months ago (spring-time) here in Washington, but don't recall hearing it this summer and early fall, so I'm wondering if it has something to do with the colder, damper weather. Anyways, here are my clues:

-Steering wheel vibrates (not violently, but..) when accelerating, decelerating, and turning at low speeds.
-While vibrating, I also hear a medium/high pitched humming sound coming from the front-end (even with the windows up).
-This is while accelerating in first or 2nd gear, while in auto or tiptronic mode.
-Also while decelerating, starting at 20mph or so, whether I'm breaking or coasting to a stop.
-And it seems to intensify when turning either direction (while turning moderately or sharply at various (safe) speeds).
-Car sounds and feels normal at idle.

-I have enough psi in the tires, and check frequently.
-When I noticed the problem off/on early this year, I rotated the tires, but it didn't help the sound. Eventually it went away.
-Not sure if it's weather-related, but regardless I know this isn't normal. I know far from everything about cars, but know more than average.

Where should I start? Any advice and help is greatly appreciated!!!

Mark
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'04 A4 3.0 QUATTRO ULTRA-SPORT (BRILLIANT RED)
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MikeakaEscobar
Junior Member Join Date: Feb 2008
Posts: 3

Yup sounds like the same exact thing

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I am having the same exact things happening. Everything is identical from the low speed noise to the turning of the wheel groaning noise.

I believe it has to do with the hydraulic steering system, though I do not know why the noise happens when traveling at slow speeds also.

So what I have noticed. Upon start up if you open the hydraulic fluid fill cap, you will see some bubbling. If you turn the wheel all the way right and left a few times and go back and look in the hydraulic reservoir, it will look like the head on a Guinness beer. (I do not recommend drinking no matter how tempting).

Then I have left the cap off and the car running for about 10 minutes. The bubbles went away. I put the cap on and no noise what so ever.

I guess people would say that in those 10 minutes, the car warmed up. But I have driven 30 minutes and still had the noise when I got to my destination.

So my very uninformed opinion it has something to do with air getting in the hydraulic system when 1st starting the car. It is directly related to the cold weather as well. Soooo maybe it’s a bad seal on one of the lines..... I am grasping at straws.... I need help!

 

hmm most likely it has to do with the fact that the hydraulic fluid youre using is mineral oil which all german cars use and have to use , from what i know mineral oils are more likely to react with cold weather and get thicker which could make it difficult for your pump to work with....but that just my guess i've had my a4 for 2 years now and havent seen this problem though, but then again i always let the car run for 15 min before i drive.

 

I'm experiencng the exact same thing. I originally thought it might be unbalanced tires so I had them rotated and balanced. I did get a reduction in the noise, but it is still present. I have yet to dive into this further. I've also noticed that i occasionally get a slight growling noise during hard acceleration. It starts at lower rpm's, but the car still boosts and no power is lost (atleast it can't be felt). I doubt that these two issues are related but was curious if anyone else is experiencing this also.

 

Cold weather noise is usually caused by cold/worn out belts (im my experience). Pop the hood next time and take a listen when it starts. Does it go away when it warms up? I lived in Canada when it would get -40 overnight and the difference between cheap and quality belts were obvious at that temp.

 

The Bubbles in the fluid in the reservoir happen because air is getting sucked into the system at some week point. I had this same problem and after replacing my PS pump (not exactly an easy thing to do on your own, but way cheaper than having someone else do it!) My steering rack started leaking, so I replaced that... and since it was cold outside, and I didn't want to tackle that job, I had it done and it was about $1400. not fun... So, I would search this forum for advice on power steering issues. there are a lot of threads about this. and I would buy good hose clamps and make sure all of the low pressure lines (rubber lines from the reservoir to the pump) are secure... if you still have bubbles in your fluid. It could be coming from a bad seal in your rack... good luck.

 

This is what you do..... ALL OF YOU.....

Take a pick. Poke a small hole a the bottom end of your bellows boots. The boots next to your tie rod ends, connected to your steering rack.

If you have fluid there... You will need a steering rack.

If not.... You most likely need a pump