Sudden loss of oil pressure

[48ply1stcar]

This morning I drove across town (5 miles) to give the old girl a tank of non-oxygenated gas. I checked oil at the gas station and I was a quart low. I decided to wait and put in the oil when I got home. Half-way home I realized I didn't have any oil pressure.

There weren’t any unusual noises, just regular loud.

I pull over shut it down and put in a quart of oil. When I started the car there was a little pressure.

Tomorrow I’m going to start by changing the oil, and checking the gauge with a parallel gauge. I also think I read a in the forum something about a plugged oil filter.

Tell me guys (“guys” in a gender neutral way) what else should I check.

[1941Rick]

Unless you changed to a full flow oil system you have a "bypass" filter and if it were plugged it would not cause your oil pressure problem. Check your gauge like you indicated and the check the oil pressure valve spring.

[Jerry Roberts]

Check the oil level again . Perhaps you did but didn't mention it . If it is real low , check for leaks , like the hose to the oil pressure gauge . If all is OK , try another gauge as mentioned above .

[james curl]

Some time back I lost most of my oil pressure coming home from a city 25 miles away, checked the oil and it was full. After I got home with about 12 to 15 PSI at 50 mph I pulled the oil pressure relief valve retaining nut and the activating spring came out in three pieces. Got a new spring and plunger from Jim Terrell at Terrell Machine in Deleon, Texas.

[48ply1stcar]

This morning I top off the crankcase, hooked up another gauge and I had 36 psi at idle. Then drove to the car show. The oil pressure dropped to about 10 psi after three miles.

I used a quart of oil to drive 8 miles. Another quart, 2 pitchers of beer, and 2 pitchers wings to drive home. I guess that was the first and last show for this year. Time to rebuild.

Edited July 30, 2012 by 48ply1stcar
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[greg g]

where is all that oil going????

[48ply1stcar]

When I decelerate, the blue smoke qualifies me as a Minnesota mosquito control agent.

[greg g]

That would indicate worn rings and or valve guides allowing oil to be pulled into the combustion chambers under high vaccum (closed throttle medium rpms) conditions.

Do you have visible mist or vapor/smoke exiting out the oil fill cap when you shut it down?

The drop of oil pressure as engine heat rises also indicates worn main/rod bearings.

Since its the fluid pressure of the oil a cushion of fluid between metal surfaces and pressure keeps the cushion plumped so to speak, it probably time to start thinking of a rebuild.

Thicker oil and or some STP stuff may assist to keep it going this driving season, but a winter project likely looms in your cars future.

[48ply1stcar]

It's time I took that $35 motor that I dropped into that car in 1968 and had a meaningful relationship with it. The car sat from 1969 until 1995. I was on the road in 97 without taking the engine back out. So I got 15 years out of a $35 engine. Not bad. I hope to use the ideas that I have learned in the past 15 years and those things I've learn on this site to finally get this car the way I want it mechanically.

[Young Ed]

Harold I know a good guy right in your backyard. He built the engines in both my mopars.

[48ply1stcar]

thanks Ed, I spoke to him las year.