I put a cam in my car last summer. I reused the O-ring that was in it, that is on the pick up tube, I know DUMB!! Well now when it gets to temp my oil pressure fluctuates and it gets a tick. I have been told its that wonderful decision I made with the O-ring and not putting a new one in it. So I am doing that now but was wondering if it could have hurt the oil pump or if the oil pump could be going bad to? Do they go bad very often? Oh and its a 2002 ls1 and has about 600 miles since I did the cam.