Cummins Oil Pressure

[bmac]

Splashed the boat today, didn't have time for a run but noticed a few things I thought odd....QSC 500's...Port Engine Oil Pressure 80 psi, Starboard 60 psi, 800RPM idle, normal operating temperature. Last year both ran at 60 psi, only work done was oil change and filters. What should I be looking for?? Also odd, on the smart craft, at idle, the port engine showed 14.7 psi bosst, the starboard 0. I've never looked at boost at idle before but I do recall a difference in boost pressure indication at load last year. When I put the boat in gear, either direction, noticeable vibration on the port side. could it be related to the oil pressure issude??? Any ideas would be appreciated.

 

[Asureyez]

I love these word games ...

At idle there wouldn't be much boost. Bet we have some sticky gauges ... what is the local temp at the boat?

IS the exhaust to Turbo gasket in tact?

What is the OP at the analog gauges at the engine? Do they agree with the dash board and smart craft?

What was done with the oil this spring?

 

[Lazy Daze]

14.7? That's interesting. That's 1 atmosphere, right? There's some kind of correlation here; something about how the computer measures the pressure vs how it displays it? Am I on the right track?

 

[bmac]

I would expect there's no boost at idle. I find it curious that the port engine is indicating atmospheric pressure while the starboard zero. I was wondering if smart craft had a choice between psi and psia and could be selected seperately for each engine :huh:. I'll have to look at the gasket. Local temp today was about 60F. Analog gauges on engine and dash for OP mach the digital indication. Oil wasn't touched this spring. :smt100

I love these word games ...

At idle there wouldn't be much boost. Bet we have some sticky gauges ... what is the local temp at the boat?

IS the exhaust to Turbo gasket in tact?

What is the OP at the analog gauges at the engine? Do they agree with the dash board and smart craft?

What was done with the oil this spring?

 

[bmac]

Maybe, i just don't know if there's a choice between psi and psia in smartcraft for each engine independently.

14.7? That's interesting. That's 1 atmosphere, right? There's some kind of correlation here; something about how the computer measures the pressure vs how it displays it? Am I on the right track?

 

[Lazy Daze]

I would expect there's no boost at idle.

I'm sure you're right on that. Besides, you'd know if there was boost - you'd hear the turbo spooling.

Do you guys with turbo diesels run EGT gauges like we do on trucks?

 

[bmac]

I think the smart craft shows EGT.

I'm sure you're right on that. Besides, you'd know if there was boost - you'd hear the turbo spooling.

Do you guys with turbo diesels run EGT gauges like we do on trucks?

 

[Lazy Daze]

You mentioned the oil was changed. Did you do it? If not, what's the chance your service guy used two different weights of oil? It's probably a long shot and I wouldn't think it would explain a 20psi difference, but...

 

[bmac]

Nope, I did the oil and filter changes. Used 15W40 Valvoline Blue, levels are correct.

You mentioned the oil was changed. Did you do it? If not, what's the chance your service guy used two different weights of oil? It's probably a long shot and I wouldn't think it would explain a 20psi difference, but...

 

[Converse48]

While you're at it.... 800 seems like a high idle. Mine idle at 600 RPM. We have the same engines, right?

 

[bmac]

Yes we do Tim. My low speed idle is set at 580 and my normal idle is 800. That's the way it was delivered. What are you normal oil pressures at idel?

While you're at it.... 800 seems like a high idle. Mine idle at 600 RPM. We have the same engines, right?

 

[Converse48]

Yes we do Tim. My low speed idle is set at 580 and my normal idle is 800. That's the way it was delivered. What are you normal oil pressures at idel?

I don't recall off hand. I'll check this weekend!

 

[Sum Escape]

My QSC 500's idle at 600RPM and have about 25-28lbs of pressure at idle. They do vary between port and starboard by 3-4 lbs.

 

[bmac]

I've got to get the boat out for a run Saturday and see what everything looks like after everything is warmed up and running under load.....then I'll panic if the pressures remain where they were. I'll post back if necesary, thanks.

 

[Robski97]

Brian,
My idle is 600. SLow idle is 550. My post oil psi is 67 my stb oil pressure is 77 . Always has been this. I have notes from day one . I did notice on some starts my stb motor is another 10 -15 psi higher. Im pretty sure I verified the pressure at the mechanical gauge at the motor. If i shut the motor off and restart sometimes it drops . Hasnt happen this year yet ( only 4 trips to date ) But has happened over the last 3 years....


Rob

 

[Hampton]

Is there an oil bypass valve to relieve excess oil pressure? If so, one may be stuck open or the other one stuck closed.

 

[Robski97]

John,
I thought the bypass was in the filter itself. After the filter was changed it still occured ( in my case ) I did have similiar problem with my 34 da where the filter was restricting flow. ( was a bad filter ) But that was a consistant oil pressure issue.

Rob

 

[Cuttin' Edge]

Brian -
Looking at the year of your boat - should still be under Cummins Warranty - have them come out.... By me in Milwaukee, they are great... Just call them direct and have them look into it. Plus, if you bought a new filter this year - and there is something wrong with it - the service guy *should* replace it and all that n/c...

 

[Cuttin' Edge]

As a PS - I have noticed a bit more vibration at idle on mine this year than in the past - but haven't looked too much into it.