I put a new oil pressure gauge in the jeep. It is the mechanical type and I replaced everything from the gauge to the fitting in the block. At idle speed I only get 5 psi and at highway speed I get about 20 psi. That seems way low to me. That's with new 10/30 oil and a new filter. Engine runs quiet though.

Gerry

Gerry I doubt your engine would be quiet if it only has 5lbs of oil pressure. Somewhere or other something isn't telling you the truth about the pressure.
When installing those aftermarket mechanical gauges I always take the tube loose from the gauge and start the engine to fill the tube up with oil..then I shut her down and install the tube to the gauge.. Just to take any compressable air out of the reading system.. Did you do that or is the tube still full of air?

Outside of that perhaps the gauge itself is faulty.. Also I never purchase a gauge that reads higher than 60lbs and I make sure to get a gauge that has a 180* or higher reading for that 60lbs. The longer the sweep is, the easier it is to get a GOOD reading of the actual pounds of pressure.
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

The gauge is a Stewart Warner that goes up to 100 psi. I definitely have air in the line so I'll do what you suggested. Thanks Big Jim.

Gerry

Air in the line will affect your pressure reading. For the most part Oil is not compressible, where air is.

The air and a short sweep 100lb gauge can give you quite a bit of varience in reading from the actual pounds of pressure.
Found out a long time ago I wanted a LOT of movement in my needle so I could get a good reading of the pressure.
However most new OEM oil pressure gauges go to the middle after 7 or 8 pounds is seen and stay there until the pressure gets below them numbers...thay really don't READ the actual pressure. They act the same as a red light would act..
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />