I didn't find anything when I did the search, but I think that this is a pretty obscure problem. I got an oil change about 3 days ago, which was much needed I was at 6000 miles since the last oil change. So I did it. I have a 91 S-10 Chevy Blazer 4x4 2 door. Close to 200,000 miles. The problem is when i start the truck when it's cold the oil pressure is at about 60, this is going by the gauge. It's always at 50 or 60 when I started it when it's cold. After driving it for awhile and it heats up the pressure will drop to 0. If I accelerate the pressure will go up to 20, but when I stop accelerating it'll drop back down to 0. I looked under the hood and there looks like oil is resting on top of the engine, but when I test the dip stick it shows up fine. I don't understand what it's doing, and I'm worried about the engine seizing. Please help me.