I just started my 370 last Friday for the first time. I am running NAPA 5W-30 motor oil with a good filter for the break in. When I start it, I get 40PSI of pressure. When the engine warms up, the pressure goes down to 20PSI at an idle. Does this seem low? My 4.8 in my DD has 175K on it and I always get 40PSI at idle (according to the gauge). The only thing that I can think of that is different is that this engine has Comp roller rockers on it. Maybe they let more oil bleed off than the stockers.

 

What oil pump? Which O-ring did you use one the oil pickup tube?

 

Stock oil pump. I used the thicker O ring.

 

Thats lower than I would like on a fresh engine...do you know what the clearances were set to?

 

Also wondering what the clearances are at? That is pretty low

 

I can't remember, but I plastigauged everything and it was all to the tight side of the allowance. I changed the oil and filter today to get all of the assembly lube out, and it was about 30 PSI at idle warm. I also cut the filter opened, and did not see any bearing material.

 

Are you checking the oil pressure with a manual gauge, or the stock cluster?

 

Obviously the lower pressure after warmup is due to the oil reaching its "HOT" viscosity coupled with the lower idle rpm not spinning the pump as fast as during "high idle".

I would verify presure with a stand alone gauge and compare to the cluster gauge.

peace
Hog

 

Yes, use a manual gauge to test the pressure. I did this and found that the cluster was reading about 10 psi lower than actual. So I pulled the needle off the stepper motor and moved it so it reads spot on now.

30psi is enough regardless. Have you taken it to redline yet? Curious what the pressure would be at high RPM. You could always upgrade the pump. My Melling high volume pump gave me an extra 15 psi.

 

I read the voltage with my flashscan. Key on engine off the voltage is .471 volts. When i start it cold it reads 1.6, and when the engine is warm it is 1.2.