Oil pressure readings..

[joshuawesl]

2003 Dodge 4.7 V8, 320,700 miles.

At 180-185 operating temperature, I'm seeing about 18-19 PSI idle. While driving normally (1700-1750 RPM) I'm seeing about 50 PSI. When the trans kicks out of OD to climb a hill or something, the oil pressure will come to to about 60 PSI as the RPM increases.

At cold start, I see 60 PSI on the nose until everything warms up.

This is with Supertech 10W30 high mileage and Engine Restore additive. Added Restore about 100 miles ago in an effort to get a little better compression out of cylinder 3. A compression test resulted in 110-120 PSI average on all cylinders except for number 3, which was about 95 PSI.

The engine calls for 5W30, would it help anything or hurt to step up to a 10W40 at my next oil change? The hot idle oil psi just seems low to me.

 

[Snagglefoot]

I’ve done something similar on my 6.0 Chev with 205,000 miles. My idle pressure went up by a few psi. My highway driving oil pressure did not change. It was 40 psi before and after. Keep in mind the pump pressure is regulated by a spring in the pump assembly. Some will say your 18-19 psi idle pressure is just fine. I would recommend you go ahead and try it.

 

[AandPDan]

For the 4.7, from the Dodge Factory Service manual, the minimum oil pressure at idle is 4 psi. At 3000 rpm, 25-110 psi.

You are fine.

 

[ARCOgraphite]

You are fine. No Problem with that idle oil pressure. Engine is just spinning the alternator, water, PS and converter pump.

The oil pump is just needed ro place oil in the bearings not "lift" or separate parts. If there is oil there
the OIL film will do the work. At higher rpm, more oil is required to keep oil in the moving parts, also the hyd tappets.

 

[DGXR]

I agree, that idle oil pressure is good. Not much work being done at idle and not much pressure on the bearings. But when RPMs come up, the oil pressure is higher and the engine is ready to work harder. That's just one reason why it's not good to lug engines (high load at low RPMs).