Should I check Power Steering Fluid level with engine running, off, warm, or cold?
 

Does it matter?

I thought my PS fluid may be low so I checked it during a work break; the car had been off for 4 hours. When I checked, it was full... Should I have checked it with the car running, and warm?

I checked the fluid level because I've been getting an intermittent groan / moan sound from the steering column the past few days. It seems that the sound comes around after the car has warmed, having driven for about 30 minutes, and only when I'm making a slow tight turn into a parking space. In addition, after having parked, if I turn the steering wheel slightly in either direction, it makes the sound as well.

I did a search here and came up with tie rod ends, power steering fluid (but as written above checked okay), and power steering pump to name a few; but I was still unsure if other's symptoms were exactly like mine.

i'm gonna say, it doesn't matter...but i wouldn't think while running isn't a good idea

Check when cold and engine off. Noise (shudder/groan) with slow tight turns
 

is most often a slight binding of the QTR driveline. This shows up most often when tire tread is worn low, or with low profile tires with stiff sidewalls.

Groaning while parked may indicate an issue with the rack or pump. Have you noticed leaks on the ground? How about fluid use, with no visible leaks? You don't say how many miles are on the car, or how many owners, but depending how the car was cared for before, there is a chance the rack or pump could have an issue.

Welcome to the Groaning Power Steering Club! We'll get you fitted for a jacket in a minute, first
 

to check the fluis: the car is supposed to be cold and the wheels pointed straight ahead. REMEMBER - this is a special Audi fluid. Do not put any other kind in the system or you WILL have a problem.

This is somewhat common (I can think of several threads, one or two by me - search for "power groan" or something to that effect). I had it diagnosed by the dealer a month ago and they said it was the PS pump and it was starting to fail. I couldn't get it replaced because I am out of warranty and my extended warranty company will only replace broken equipment - not almost broken stuff.

If you're still under warranty, have the dealer take a look.

she's back ;-)

Re: Check when cold and engine off. Noise (shudder/groan) with slow tight turns
 

Thanks April.

Tires are fairly new.

It has about 47k miles and one previous owner.

No visible leaks & PS level checked full.

Should there be other symptoms I should watch out for if it were the pump?

2nd. I noticed too! =)

If it's the pump, you can usually feel a vibration when it's working hard (dry turn).
 

There may be a rebuild kit for the pump, but I'm not sure how much of a savings that would be over buying a new one - given labour is often a large portion of the cost.

Racks usually leak, and are less prone to making noise. So if the fluid in the tank remains constant, then I would look to the pump first. If fluid is vanishing, but not on the ground while parked, then the seals may be leaking into the bellows at either end of the rack, and then the fluid is dumped while under way.

As M-brown says, the correct fluid is critical. A lot of dry turns (turning the wheels while the car is not moving) will take a huge toll as well, especially on heavy cars with wide tires.

I try to never turn the steering wheel unless the car is moving even just a tiny bit. Likewise, if I'll be turning in the opposite direction (like say a 3 point turn), I pre-cock the wheel in the direction of my next turn, as the car is coming to a halt. Maybe I'm paranoid, but I try to change the fluids every couple of years. I don't have an Audi now, but the ZF rack and pump in my car lasted around 200,000 miles before replacing the rack and rebuilding the pump.

I have something similar in my car, do you
 

happen to hear or feel the noise/vibration when you get in and out of the car (engine off)? Can you feel it if you rock the car sideways?

I have that strange noise in my car too, and I am definitely sure that it is not related to the Power side of the steering system. Neither is it the tie rods.

I had the car checked by an independent mechanic and his conclusion was that this had something to do with the steering rack outer seals... I thought this might be it, but with a new rack at close to $1400 I've learned to live with the noise.

Please let me know about this. I want to feel I'm not alone in this one!

Andres

Nope... haven't noticed those symptoms <knock on wood>