Check the voltage, as Klaus suggests. If that is okay, just replace the starter and be done with it.

So many times I read posts about people who have problems with their 850, but have managed a work-around, and live with the problem for extended periods. The point of my original response was that living with this problem is most assuredly going to further damage your car. Given the declining values of our cars, a repair requiring spliting the engine and transmission may doom the car. So fix the problem before it gets to that point.

I had a Honda that the starter started "going out" on. It would either make a horrible grating noise and not start, or start perfectly fine. It finally died on me when we got about 5 inches of snow one morning. It turned out when I went to change the starter that the spring to engage the solenoid had just gotten twisted and broken, so it would only partially engage & chewed up some of the teeth on my flywheel from where it had been grating against it. So I guess what I'm saying is that even though you changed it, it could still have a bad solenoid/spring combination that only engages sometimes.