i have an 01 dakota with the 4.7 , the engine has 260000 kms on it it , it worked great on the road but the other night i was idling through a back road and at low rpms i lost oil pressure, give it some fuel and the pressure is back up later on i noticed a knocking coming from the engine , it doesnt sound like the bottom end ( rod) knock, it soulds like top end like a collapsed lifter, would a bad lifter cause oil pressure loss?