We recently purchased a used 2007 A4 Cabriolet for my wife and have been getting a random power steering groan. It usually occurs after the car has been driven and warmed up when driving at slow speeds (parking lots). I have not noticed it when the RPMs are up or when cold. Any thoughts? The belt looks good and has good tension and I replaced some of the fluid by suctioning the fluid in the reservoir and refilling with Pentosin CHF11S and repeated 3-4 times alternating with running the vehicle and turning from stop to stop. Not a complete flush and it didn't seem to help. Flow through the reservoir looked OK and I didn't see any air bubbles. Any help would be appreciated. Thanks.

 

Is it groaning at the rack end? or normal side to side movement?

it is normal at full left or full right. The B7 A4 doesn't have rack or pump problems. Sometimes the servotronic relay goes bad.... but you would feel like you lost power steering at slow speeds with no noise at that point. You seem to know what your talking about, but we always encounter alot of new Audi / Euro owners who just aren't used to their akward operating behaviors

 

Check the power steering fluid levels. Be forewarned that you'll need special mineral oil if it is low. Happened on both of my audis before.

 

Top the power steering fluid off just above the MAX level. Check for leaks too if it happens often.

 

Be carful with the fluid. You will have to get it from the dealer or a European auto pars place. The wrong fluid will trash the system. I bought a bottle and have it at home just in case. The Jetta I had, used the same stuff, and I had to top it off about every two years. If I remember right, there is a TSB about the steering and in it the TSB talks about filling the fluid and the procedure to get rid of bubbles.

 

When I topped off my steering fluid in my old audi, I remember I had a really hard time finding the right fluid. I think there's two colors - green and pink, and if you have one, you shouldn't mix it with the other. But don't go out and just buy the right color one, do your research, and see which spec you need, if there is such a thing. I just remember it was a pain in the *** to find the right one.

 

Check for any loose hose clamps or hars hoses on the suction side of the pump. real easy for air to be sucked in causing aeration of fluid & noise.

 

Does anyone have a DIY process for flushing and filling the A4 B7 power steering system? I have seen some for other models but not this one. We are still having steering groan when turning, not just at the stops but in between too. I would like to give this a shot before taking it in to the shop. Also, is there a screen or filter in the bottom of the reservoir that can be cleaned or replaced? Thanks.