Oil Pressure - Cummins QSC500

[shinsr]

Have a 44da with cummins qsc 500's - ran boat for a short while today and noticed that the oil pressures were farther apart than usual - ran (at cruise speed and WOT) 47lbs Port and 74 Stb. They were never identical but were closer than this over past 3.5 months. Checked the fluids upon return and both engine levels were perfect. Temps were fine on both engines as well. Anything to worry about here?

 

[alnav]

I have had a similar problem on one of my engines ever since I got the boat on an intermittent basis (happened again today as a matter of fact). One engine's oil pressure is 13.5 PSI greater than the other. In my case the same engine's boost pressure is high by exactly the same amount and reads 13.5 PSI before the turbo even kicks in. Interesting that your overage (27 PSI) appears to be exactly twice mine. It doesn't happen that often and I've never been lucky enough to have it happen with a tech onboard. I have discussed it with the dealer and a Cummins tech and they both told me it was probably a transient sensor issue although Cummins did record the issue in their electronic records of my engine, which is probably a good thing just in case. It doesn't seem to have any impact on operation or performance in my case.

 

[Asureyez]

told me it was probably a transient sensor issue .

Means corroded contacts on guage or sending unit. Try cleaning up the contacts and see where it goes.

 

[shinsr]

Thanks - checked my Cummins survey - says normal operating range is 30 - 77 lbs (cant beleive that it is that wide but it is!). I will watch it as performance is perfect, if it gets any greater I will get them down.

 

[bmac]

My oil pressure varies significantly as well; yesterday Port 55 psi, Stbd 72 psi. I've also have seen them match pretty closely....got me.

 

[shinsr]

Thanks Brian - good to have a sanity check - seems like a cummins mystery. I will watch it but am not going to go crazy yet - I have another poltergeist on my coolant overflow bottle - but thats going in another post in 2 minutes!

 

[Sum Escape]

Have a 44da with cummins qsc 500's - ran boat for a short while today and noticed that the oil pressures were farther apart than usual - ran (at cruise speed and WOT) 47lbs Port and 74 Stb. They were never identical but were closer than this over past 3.5 months. Checked the fluids upon return and both engine levels were perfect. Temps were fine on both engines as well. Anything to worry about here?

My oil pressure on the starboard side has been about 10 lbs higher than port (after warm up) since new. I did have one time that I had erratic readings too....way too high boost, oil pressure etc on port side. Restarted engine and all was fine. Cummins tech said to start starboard side first as this is the master computer for the Smartcraft. Not sure if this is legit but have never had the issue reoccur after using this procedure.

 

[shinsr]

Thanks - I will run her again this weekend and see if it is still the same.