Don't overlook an oil light. That CAN lead to serious engine damage real quickly. The best test is to measure the actual oil pressure with a mechanical gauge that screws in place of the sending unit. If it shows good oil pressure, just the sending unit is defective. That's not uncommon. If pressure really is low, and increases when you increase engine speed, worn crankshaft and connecting rod bearings are the most common cause. Everything will still be getting oil but when it isn't under pressure it can't isolate the moving parts from each other.
Low oil pressure will cause the hydraulic lifters to not pump up too. The clattering will sound like a typewriter. (Typewriters were real common only ten years ago. Really!)
Monday, May 2nd, 2011 AT 4:58 PM