Oil Pump How-to

How difficult is it to change an oil pump?

I have a 97 GV 3.3L that makes a knocking noise for about 1 second after start-up. Obvoiusly oil starvation. I've seen on here that pick-up tubes often get clogged on here and I suspect that's the prime cuase, but while I am there is it easy to get to the oil pump and would it be worth it to change it as well?

Another thing that happened twice during the summer was that the oil light came on and the chimes went off while I was stopped at a light. The pressure had dropped enough to sound the alarm, but the oil level was good. Another reason I suspect the pick-up tube and/or oil pump.

It runs fine and very quiet the rest of the time and I want to keep this thing around for a while.

Any tips on getting to the oil pump and how difficult it may be would be greatly appreciated.

Thanks in advance.

Best thing to do is put a manual gauge on it to check the oil pressure. The oil pump is housed in the timing chain cover and the pump rotor is turned by the crankshaft. That's a lot of work if it does not need a pump. You probably have a bad oil pressure switch causing the light to come on. Noise at start- up is usally caused by oil draining out of the filter after engine is shut down. You might try a different brand of filter for this.

Thanks, JPB. Next oil change I'll try a different filter, it's almost due anyway. I'll see if I can borrow a pressure guage as well.

Follow up:
The Oil filter did the trick, I've always been using either Puralator or Fram, but I got a K&N free with an oil purchase deal once and that was the culprit. Supposedly K&N is a better filter, but the other day I changed the oil and I replaced it with the Puralator. Now it no longer makes that awful noise at startup, even on the cold Pittsburgh morning we had the other day. Looking back, the noise started after I began using the K&N.

Thanks again JPB, I was about to tear out the oil pump.