The weather has been down in the teens lately by me. Everytime I drive when it is this cold, I get a wierd rubbing sound when turning the wheel, even only slighty. It can get quite loud. It gets louder and higher-pitched the more I turn and the faster I roll. When I am on the highway or at higher RPM's, it is still there but not as noticable. This occurs even after the car has warmed up. When the temperature goes above 30 degrees or so, it goes away or is so low you have to strain to hear it.

I checked all the fluids (PS was my first guess), but everything is within the normal range.
There is no burning smell or any other noticable symptoms. The tires are not touching any part of the chassis, even when turning.

I'm thinking it's: a) PS pump, b) CV joint, c) brakes or d) the Differential (I have Quattro).

I have a service scheduled, but I am concerned that I am making something worse or causing a safety hazard in the meantime, as I drive the car daily.

Any help or suggestions would be greatly appreciated. Thank you!

 

OK, so after the car had been sitting for a bit tonight, I checked the PS fluid again. It was just above the MIN line. I added a little more (maybe around 2 tablespoons of standard STP PS fluid from the local auto parts store - hope that's not a problem). Now it's about 3/4 the way up to MAX. Started up and went for a spin. The noise is either gone, or it's so low that I can't hear it. Everything sounds "normal" now, or at least how I remember prior to having this problem.

The only explanation I can think of is that the extreme cold has some effect on the PS fluid causing it to contract or maybe become gummy. Or, some moisture got into the PS reservoir/pump and froze, causing other problems. Either one could explain why it wasn't an issue when the temp was above freezing. I only hope that I haven't done any damage to the PS pump at this point.

Thank you to everyone who took the time to read. Your thoughts are still welcome if anyone has any.

 

That's good that you found the problem, but you created a new one by adding standard ps fluid. Audi's HAVE TO use mineral based ps fluid, which is available at the dealership, online, and a few select local places(if you're lucky.) If I were you, I would have the ps fluid flushed so that you're running only the correct fluid.

And it might be a good idea to buy a bottle of ps fluid as well as G12 coolant to have just in case you ever need it.

 

Crap. I was afraid of that. I will definitely have them flush the system. However, I'm back to square one anyway because the noise is back. The temp dropped to around 9 degrees last night and I wanted to see if it was still OK - no such luck. It seems worse when the RPM's are below 2000, and even when I'm idling, it's still there slightly. I'm going to see if I can't get the car in to the dealer sooner. Thanks for the tips.

 

My car has a PS leak and does this from time to time. I've noticed that the PS fluid is turning into "bubbles" in the resevior, and i think this is the cause of the problem. Here lately with the cold, I have to add PS twice a week, which usually ends up on my driveway or wherever I park it.

 

Right - I happened to check the reservoir after coming back from a short drive today and the fluid was all bubbles and opaque. After it sat for a while it turned darker (and would probably be clear had I not added the standard PS fluid a couple days ago). I assumed the cold was somehow affecting the fluid but maybe it's causing a seal to shrink somewhere in the PS system. Will check the driveway for leaks next. Appointment is scheduled for next week. Going to see if I can't find some of the mineral-based fluid in the meantime. I only hope I haven't damaged the pump or won't cause damage if I keep driving it until the service. What sucks is they don't mention ANYTHING in the manual for fluids other than the note about using synthetic engine oil only. What are you supposed to do if you need to add other fluids in a pinch? Maybe I can use that argument to knock some dollars off the bill...