EMD Low Oil Pressure
EMD Low Oil Pressure
(OP)
Hello,
We have a pair of EMD 20-645 E5's and they are running fine with about 20,000 hrs. on each. The stbd engine seems to take a lot longer to prelube than the port and after running at temperature and at cruise speed (about 800 rpm) for a while the oil pressure in the filter pots goes down to zero! The LOP in the engine is fine, around 70 psi, but the filter pots is where the problem is. Also, when the power is pulled back, the LOP in the pots comes up to 20 or so but the outlet is a few psi HIGHER than the inlet. Dirty filters would cause the opposite. The filters have been changed with the same results. The heat exchanger pressure reads the same, zero, as the filter pots. Any ideas? We've had mechanics here working on it and no joy.
Thank You,
Dan
We have a pair of EMD 20-645 E5's and they are running fine with about 20,000 hrs. on each. The stbd engine seems to take a lot longer to prelube than the port and after running at temperature and at cruise speed (about 800 rpm) for a while the oil pressure in the filter pots goes down to zero! The LOP in the engine is fine, around 70 psi, but the filter pots is where the problem is. Also, when the power is pulled back, the LOP in the pots comes up to 20 or so but the outlet is a few psi HIGHER than the inlet. Dirty filters would cause the opposite. The filters have been changed with the same results. The heat exchanger pressure reads the same, zero, as the filter pots. Any ideas? We've had mechanics here working on it and no joy.
Thank You,
Dan





RE: EMD Low Oil Pressure
RE: EMD Low Oil Pressure
RE: EMD Low Oil Pressure
I'm sorry i haven't gotten back sooner but it's hard for me to get access to this computer. It seems the chief is ALWAYS on it! Anyway, I've been trying to find out if we have a Michiana filter arrangement and I'm not sure. Each engine has a BIG steel tank (pot) that hold 19 filter cartridges each. This "pot" is about 48" in diameter and about the same height with a domed lid that's held on by a 12" wide steel band and a row of 1" bolts all the way around. I wish I could attach a picture. Anyway, since your replies I've been paying more attention to the problem. It is as I said before: the pressure is about 30 psi in/out at 400-600 rpm but then drops off TO ZERO! on the port engine only. I'm still looking for the problem. Obviuosly the LOP is NOT zero or we would not be running. Pressure at the engine gauge in 80 psi when cold. Thanks again, Dan
RE: EMD Low Oil Pressure
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2. The LO system is divided into 2 systems, the scavenging system that circulates the oil from the oil pan through the LO cooler and the LO filter then to the strainer box on the front of the engine. The cooler and filter tanks are protected by 20 psi relief valves the maximum pressure in this system shouldn't be much higher than 20 psi and will be much lower when the oil is hot. The engine pressure system and piston cooling system pickup their oil from the strainer box and circulate through the engine. The pressure system should be 60 to 70 psi when hot.
3. Both system should have separate pre-lube systems, on the scavenging system to fill the cooler and filter tank and on the pressure system to check the flow throughout the whole system.
RE: EMD Low Oil Pressure
Bill
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"Why not the best?"
Jimmy Carter
RE: EMD Low Oil Pressure
2. If you are going to check the by-pass valve, mark it before you take it out. If it goes in backward the first time you start up a cold engine the oil pressure will crush the filter elements and blow out the tank divider. Sold a lot if new tanks that way. In one case on a engine with plugged filter elements (water), and an inoperative low LO pressure switch. They wiped out the turbo in about 2 days operation. the turbo filter was picking up all the dirt and has no bypass.
3. Make sure all the air is vented from the tank. There"s a vent valve in the cover.
RE: EMD Low Oil Pressure
RE: EMD Low Oil Pressure
Why do you say that? I'll be back onboard wednesday afternoon. I'd love to be able to go right to the problem area and do some probing but I'll need to explain my actions to the departing chief and the port engineer. On my last hitch the QMED & I tore apart the prelube pumps (Viking) and replaced one with a new unit. They still only develop about 5-7 psi each and no change on time required on the port engine. Also, the soakback pumps only run for 6 minutes on prelube before shutting down; about 30 psi though. I have to reset them several times before startup. I'm sure I can change this setting in the control box but again, being the new guy, I'll have to explain it. How long should they run? Thanks for all your help guys.
Dan
RE: EMD Low Oil Pressure
The only engine that have soak back pumps that run all the time the engine is shut down is on generator engines where the pump is part of the stay warm systems and they have a divided discharge where some oil goes to keep the oil cooler full. When they run under load the controls during a shut down will unload the engine, open the breaker, run the engine down to idle and leave it there for 11 minutes to help cool the turbo before stopping the engine. On these engines if a mechanic changes some parts and wants to pre-lube the engine, he has to get his pump out of the truck, open a oil pan hand hole cover and drop the suction hose in and connect the pump to the engine pump discharge elbow. You see priming the engine is not that important to do all the time.
RE: EMD Low Oil Pressure