Groaning sound from steering

[Gary Gaukler]

Wondering if y'all can help me diagnose this.

2001 S, 105 Kmi. From time to time, when I turn the steering wheel, there is a groaning sound coming from the front of the car. It's most audible when I coast to a stop; when accelerating it's difficult to hear because of engine noise.

It sounds like a power steering pump, but that can't really be it because the pump is rear of the driver, and this sound is definitely coming from the front.

P/s fluid level seems fine. No drips. I jacked up the front but could not find anything obviously amiss. I have not yet taken the plastic underbody off, but there is no evidence of leakage anywhere around the steering rack.

Any ideas? Maybe just air in the p/s lines?

Thanks,
Gary