My allroad started making a peculiar noise when turning hard right last winter. At first the noise was intermittent - it did not occur with every hard right turn. During the colder months the noise was consistent - pretty much happened with every slow hard right. The noise has subsided with return of warmer temps.

I have checked the power steering fluid. The noise does not occur with left turns or with steering at normal driving speeds. The noise is fairly loud - probably around 1000 - 1500 Hz in pitch (not a squeal, a little higher pitch than a groan). I can feel some resistance in the steering when the noise occurs.

I am guessing either the pump or hydraulic actuator/cylinder is going out. I have read the A6 series are notorious for low speed steering noise. I need to know how serious the problem may be (whether it needs to be repaired ASAP). Any suggestions for a definitive diagnosis and remedy would be greatly appreciated.