I swapped a used engine into my car and I keep having oil pressure problems. It reads 5 PSI on my stock gauge (tried 2 different senders) then I used a mechanical pressure gauge. Stilll read little to no pressure. These were all readings on the back of the intake manifold. I checked the oil level and its good. The only think I did to the engine was pull the distributor, and the only thing I could see is that it didn't engage the oil pump possibly. Otherwise I'm baffled. The car starts and runs fine- I just don't leave it on for more than a few seconds due to the low oil pressure readings. Ideas?

 

If you still see low pressure with a mechanical gauge you definately have problems.

Maybe a bearing gone or a pump issue...?

 

Pull the distributor again and make sure the pump is engaged. If it isn't, you can jam the pump shaft so that it doesn't turn the pump. In 35 years of doing this stuff, I've done that once - this year.

 

But if hes getting some pressure the pump has to be moving...!?!?!?!

Unless its got a gremlin that pumps a small volume of oil into the system

 

The 5 PSI may just be a problem/flaw in design with the sender. The Mechanical gauge didn't move at all when installed. Sorry for the mixup.

 

Yep, the oil pump wasn't fully engaged. Now has about 60 PSI on both mechanical and electronic gauges.