The Stovebolt Site Forums The Shop Area Engine Shop Oil Pressure

Yesterday I primed my new engine with an old distributor shaft and an oil pressure guage in the oil pressure outlet line. The guage registered 15 lbs. Very little oil was visible in the rocker arm area. Today I installed the distributor and the line to my new oil pressure guage on the dash. I now have zero oil pressure at the guage. The new oil pressure guage has a plastic see-through line and oil is not traveling through the line. I can see bubbles of oil but the line is not filled and there is no oil pressure. What happened? The new engine is a '52 235 from a powerglide car with hydraulic lifters I installed in my '40 pickup.

By spinning the oil pump and seeing 15psi on the gauge I would think you are OK (assuming the gauge is good). Cold oil coming out of the rocker arms takes a long time when only spinning the pump. I saw the same thing with my 235. Once you get the engine running and the oil warmed you will see alot more flow from the rocker arms.

You won't necessarily see oil in a translucent plastic line unless you have purged the air out. This is a dead-end pipe. When the oil pushes on the air it will compress and allow the gauge to read. You can purge the line by pressurizing the oil system and loosening the line right before it goes into the gauge until oil comes up the line. Just like bleeding air from brake lines - except an oil gauge will work correctly with air in the line.

Why the "new" dash gauge doesn't register is another matter. You could test by setting the regulator on your air compressor to 15 psi and pressurizing the gauge to see if it responds. Maybe you have a crushed farrell on the plastic line?

Keep checking it'll come to you.

Paul

Are you saying you started the engine and the gauge shows no pressure? If so, the distributer may not be seated in far enough to engage the oil pump.Loosen the pinch bolt on the base of the distributer at the rear,push down on the dist while a helper cranks over the engine,should drop down slightly if it wasn't in all the way. Pull the coil wire and ground it so you don't get buzzed.

I am sure my oil pressure gauge is correct and the distributor tang has engaged the oil pump. It just seems to have quit pumping. Any other ideas would be appreciated before I take the oil pan off.

If you're certain the pump is engaged, the next step is to drop the pan and check the pump and plumbing. When you drain the oil, save it in the pan. You can then check the pump by setting it in the oil and turning it with the priming shaft attached to a drill motor.

Is the engine running or not?

Paul

The engine is running