Originally Posted by audiophile
First thing I would look at would be the oil pump, specifically the pick up strainer. I had the same problem last year until it dropped pressure all together (90 miles from home). It is not a difficult fix but will take a few hours. Once the pan is off the strainer and pump are easy to access and they are not expensive. We were able to just clean the strainer and I think the pump was around 20 dollars. You will need to pick up a new gasket as well.
What happened was over time the oil that is left in the engine becomes carbon and will circulate in the oil pan. If there is to much it will eventually start clogging the strainer and make your pressure drop.
+1 on this. I went thru something similar last year with mine shortly after i bought it. Oil gauge was normal then would drop to zero. One day it started sound like my motor was one of the Power Wheel toys with the clicker deal on the rear wheels...took it to my mechanic and to the local Dodge stealership. Stealership put a new sending unit on, didnt solve the problem. Mechanic dropped the oil pan..the oil looked nasty ass..like it had never been changed (in my defense, I bought it used with 23k and changed the oil 2 days after i brought it home) Anyways, pick up tube was clogged about 70% with sludge; it started starving the motor, hence the Power Wheels noise. New oil pump, pick up tube, fresh oil and filter, pan gaskets and sending unit. I ended up changing the oil 500 miles afterwards to check for any metal shavings, which I didnt find, and hasnt given me any problem since.
Best to get it looked it ASAP before it causes you some long term effects