Oil Pressure

Scott21 · Post by **Scott21** » Sat Apr 04, 2009 8:18 pm

I have good pressure to start but it drops as the motor gets hotter.

Any ideas before I change out the pump.

Scott

Bill_F · Post by **Bill_F** » Sat Apr 04, 2009 10:04 pm

Bearings would be my guess.

Post by **wesk** » Sat Apr 04, 2009 11:06 pm

First tell us what it reads with a direct reading gage. Do not rely on the 24 volt electric gage until you have confirmed it's accuarcy.

Oil will thin and pressure will drop as the oil gets hotter. This will be even more pronounced with semi-synthetic multi weights.

Also give us some background on the engine. Just put it back together?

Scott21 · Post by **Scott21** » Sun Apr 05, 2009 7:03 am

Will go with a direct guage first. Thanks again Wes. Will let you know.

Scott21 · Post by **Scott21** » Mon Apr 06, 2009 6:31 am

With a test guage the pressure is stedy at 15psi at 500 rpm. Pressure is 30 psi at 1000 RPM. The pressure climbs steady adsyou increase RPM.

maeserik · Post by **maeserik** » Mon Apr 06, 2009 7:25 am

15 psi with a warm engine is normal , in our GPW there is a CJ3a engine.
cold 35 psi on idle, warm about 15 psi, and warm max 45 psi on high rpm
with mechanical gauge

our M38, gave 30 psi on idle and full scale ( 60 psi gauge) on high rpm so far the electric sender <> gauge are working well

i think when the gauge needle is stable, do not worry...

ERik

Post by **wesk** » Mon Apr 06, 2009 8:51 pm

15 at idle and 30 at 1,000 is very good. You should get arm readings at highway sppeds of 30 to 40.

You never gave us the numbers you attained with the original electric gage and sender. So I will suggest that if there is a substantial difference, say greater than 10% of scale then you should get a VOM and a pressure testing source and complete the troubleshooting in the TB 9-2300-228-20.

It is right here in our download sectionL
http://willysmjeeps.com/downloads/instruments.pdf