Oil Pressure for 5.9

[Ronald Miller]

I could use some help trying to ascertain what a min, normal range and max oil pressure might be.
I'm not relying on the idiot gauge in the dash.
I have a banks 0-100 psi sending unit mounted on the top of the filter housing.
I'm was getting 0.2 psi at idle and 112 psi at 2000 psi. No doubt that sending unit is goofed.

So I began troubleshooting and bought a mechanical oil pressure testing gauge to see what that would read.
I'm getting 51 psi at idle and 77 psi at 2000 rpm.
Does that seem normal for where I am taking the reading? Engine has 92K.

Very interested in getting some definitive numbers for:
Minimum:____
Normal Range:____
Maximum:____

Any help would be greatly appreciated.
Thanks much in advance....

 

[AH64ID]

Is that at operating temp?

I had a psi gauge in the block above the ECM. At operating temp you should be at ~15 psi at idle and ~65 psi above 1800 rpms. Pressure at the filter head may be a little higher.

The gauge on the dash is 100% fake.

Your readings seem high. 77 is above the bypass value, but you can get above it when the oil is cold.

 

[Ronald Miller]

Is that at operating temp?

I had a psi gauge in the filter head. At operating temp you should be at ~15 psi at idle and ~65 psi above 1800 rpms.

The gauge on the dash is 100% fake.

Your readings seem high. 77 is above the bypass value, but you can get above it when the oil is cold.

@AH64ID Thanks... When I took the reading, the truck wasn't quite at operating temp but it wasn't exactly cold either.
Worries me that PSI is so high, especially at idle.
So are you suggesting that the filter is bypassing?
Oil and filter change less than a 1K miles ago.
Would a clogged/dirty filter be the culprit here?
Thanks again!
p.s. Agreed, the gauge in dash is completely fake....

 

[AH64ID]

Get it to operating temp and check again. In addition to the oil psi gauge I ran a oil temp gauge in the filter head. It would take several minutes for the oil to be fully warm after the thermostat opened on coolant.

There are two bypasses, one for a clogged filter and one for too much pressure. When the pressure is too high, cold oil, the filter isn’t bypassed but some oil does dump to the pan to keep the pressure from getting too high.

 

[Ozymandias]

The pressure port(s) is after the filter, downstream.

 

[Ronald Miller]

Based on y'all's comments, I ran some new numbers this morning. Would be interested to hear what you guys think about these numbers. Do they still seem high and if so, what might be the cause? What should maximum oil pressure be?
The book doesn't really say. It says 10 PSI Minimum, 20-30 PSI @ Idle and above 30 PSI @2000 RPM.

Idle (750 RPM) - Eng Temp 130°F = 55 PSI
Idle (750 RPM) - Eng Temp 140°F = 45 PSI
Idle (750 RPM) - Eng Temp 155°F = 37 PSI
Then, took it out for a drive to get the engine temp up to normal operating temp.
Idle (750 RPM) - Eng Temp 190°F = 24 PSI
Park 2000 RPM - Eng Temp 190°F = 70 PSI

Thanks very much for the comments/advice. I really appreciate it.
r.

 

[AH64ID]

A little higher than I saw, but that’s also a different port than I used which is closer to the pump.

Nothing alarming thou.

 

[Ronald Miller]

A little higher than I saw, but that’s also a different port than I used which is closer to the pump.

Nothing alarming thou.

Cool - Thanks much!

 

[AH64ID]

On a warm engine you shouldn’t see much over 70 psi. There is a pressure limiting valve that opens at 75 psi. You will see above 75 on a cold engine due to the cold oil not flowing thru that valve fast enough, but it will flow enough on a warm engine.

 

[Ronald Miller]

On a warm engine you shouldn’t see much over 70 psi. There is a pressure limiting valve that opens at 75 psi. You will see above 75 on a cold engine due to the cold oil not flowing thru that valve fast enough, but it will flow enough on a warm engine.

Understand. Perfect. Any idea on a warm engine (normal operating temp of 170º F. - 230º F.) what Max Oil Pressure might be? The book doesn't say.
Thanks!

 

[AH64ID]

Not really, it will vary based on oil temp. I’d see 60-65 without towing and as low as 48 pulling a long graded loaded heavy on a hot day.

You’ll get used to what is normal.

 

[Ronald Miller]

Not really, it will vary based on oil temp. I’d see 60-65 without towing and as low as 48 pulling a long graded loaded heavy on a hot day.

You’ll get used to what is normal.

Ah okay gotcha... Thanks much for the info.
Now I just need to call Banks on Monday and try to get them to replace their crazy 0-100 PSI sending unit that's spitting out erroneous readings.
Thanks again!

 

[DaveHess]

About 15 years ago, i pulled galley plug located just above the ECM and installed mechanical oil pressure gauge. Cold idle gives me around 70 psi. Hot idle around 18 psi. At operating temperature (190) gives me around 48 psi.

 

[Ronald Miller]

About 15 years ago, i pulled galley plug located just above the ECM and installed mechanical oil pressure gauge. Cold idle gives me around 70 psi. Hot idle around 18 psi. At operating temperature (190) gives me around 48 psi.

Perfect. Guess I'm right in the ballpark. Thanks!

 

[DaveHess]

I owe an apology here. The only reason I knew to tap that galley was because of the expertise and knowledge provided by AH64ID. I thank you Sir! I have lost count over the last 19 years I've owned this truck, the amount of times members have come to my rescue. I thank you all!

 

[BigPapa]

Idle (750 RPM) - Eng Temp 130°F = 55 PSI
Idle (750 RPM) - Eng Temp 140°F = 45 PSI
Idle (750 RPM) - Eng Temp 155°F = 37 PSI
Then, took it out for a drive to get the engine temp up to normal operating temp.
Idle (750 RPM) - Eng Temp 190°F = 24 PSI
Park 2000 RPM - Eng Temp 190°F = 70 PSI

I had my oil pressure sensor in the top of the filter head on my ‘95 and saw basically the same numbers. You’re fine. Drive on.