Oil Pressure

Hi Tom,
It sounds like your oil pump is loosing it's prime. Try removing the oil pressure fitting (or lowest fitting that is closest to the oil pump) and inject a cup of oil into the engine. The oil should run down into the oil pump and prime it. Replace the fitting and start the engine. See if you get oil pressure fairly quickly (within about 5 sec.).

JIm

I had a very similar oil pressure problem with my 89 Ford F-350 diesel. I had replaced the mechanical gauge plastic line from the block to the pressure gauge in the truck dash board with a 1/8 inch copper line. I was concerned with the plastic line breaking and oiling up my interior.After changing the line to copper my pressure would climb very slowly to 80 lbs. Shut engine off and it dropped very slowly too. I remove the fitting from the block. It was clear.I cranked the engine and oil shot out the open hole.I took the fitting apart. Found nothing. I FINALLY looked at the cut end of the 1/8 inch copper tubing.I used a tubing cutter on the tube to cut for length.I did NOT clean out the cut end of the rolled over burr the cuter blade made.It was nearly closed off allowing no flow or pressure to the gauge either direction.Cleaned out the burr and like magic.I showed oil pressure on my dash gauge.This tubing cutter has a flip out burr blade for just this reason...But I believed I knew better..We are never too old to learn...


Gary Parsons

You might have a sludge problem though. Have you removed the oil pan to check? Sludge can plug up the oil pump screen and other oil feed holes.
CORDiallyMike

A follow-up to my original message of 9/9/21. I wrote my message just after disconnecting both the oil pressure and oil filter connections at the engine block, starting the engine, and having no oil come out after running the engine for about 3 minutes. The next day I went back to my shop to find a large pool of engine oil on the floor. Clearly running the engine had created engine oil pressure, which I presume pushed out a plug in the block fitting causing oil to spill on my floor. To me that means my pump is working, and is creating pressure. Today I took off the "Tee" that allows both the oil pressure gauge and the oil filter to connect to the block fitting. Both those fittings have a very small hole to their respective locations, and looking at the end of the tube that runs to the oil pressure gauge there is an obvious sludge plug in the end of that pipe. I will remove that whole pipe from the back of the gauge and blow it clear.
I think I have solved my problem, and am delighted that I don't believe I have an oil pump problem.
Tom Clarke

First check to see if you have oil pressure at the special fitting on the block. Disconnect the original copper line and install your gauge right at the block fitting.

For the last several years my oil pressure gauge has become more and more erratic. First of all, it took a few minutes after starting the engine in the Spring for the gauge to register anything. Then it took 15 minutes. This Spring, the gauge didn't register anything at all. On the drivers side, front, there is a port that has a connection for the oil pressure gauge, and that has been "tee'd" so a line to an oil filter could be attached. I disconnected both the gauge and filter lines, started the engine, and no oil comes out. I suspect the oil pump has become clogged with sludge, or has failed entirely. Before I begin the removal of the oil pan, does anyone have any thoughts for me?

Tom Clarke