low lube oil pressure EMD 12-645-E5

[tugbillmaier]

thread321-290487

To CaptKhaos

I have the same problem now, I had an oil pressure of 60 psi befor I had my two 20# relief valves rebuilt, now my oil pressure is down to 38 psI. I called the people who rebuilt them and he told me that one valve had a bigger spring. I do not prelube every time only if the engine has been shut down for more than one hour. I have 14 filters in the filter pot. I am with the U.S.Army Corp Of Engineer's , the tug is one of the navys old YTB. This one was YTB-799. Do you have two 20# relief valves by the filter pot. One is for if the filter pot plugs up the oil will bypass the pot and the other one is for thelube oil cooler. I called EMD and they told me that the valves were an add on. And you should have a 40# relief valve in front of the engine. I would like to here more about your findings. this is tugbillmaier handle.

 

[dicer]

And what did the folks that did the rebuild of the valves say they changed?

 

[tugbillmaier]

They told me that one of the relief valves springs was a lager spring, but did not know what size, i am going to try and put 30 lb springs in the system and hopfuly that will bring the pressure back to 60 psi.

 

[TugboatEng]

The two relief valves you mentioned are differential pressure bypass valves and should have no effect on engine lube pressure. If I remember correctly the E5 does not have the strainer box on the front of the engine. So you should have a scavenge pressure relief valve set to open at 40psi and scavenge oil pressure should be around 45 psi. The lube pump itself has a relief pressure of 110 psi and the system should typically operate around 85 psi.