Power steering pump very noisy on cold day startup. System itself is slightly noisy under normal operation though the steering operation seems fine. Our excellent mechanic has replaced entire system including rack, pump, and hoses. Still get noise on cold startup. Seems like there is a slow deterioration of the pump over time. At wits end. Do the 1997 Prizm 1.6 have a chronic problem? (The issue with the pump started last year when a mechanic replaced one and then another and then another and finally also repaired a leak in a hose.) The car has been very well maintained and is otherwise in excellent shape.