Oil pressure has more to do with the condition of the engine. If your engine's bearings a excessivly worn, the pressure will drop. Remove the sending unit, and screw in a test gauge, you should have 5-10 psi at idle warm engine. If it's OK replace the sender, if not, you can try heavier oil. Say 20-50 or 30 non detergent!
Monday, January 7th, 2008 AT 1:56 PM