EMD 710 series

Having an issue with lube oil migrating back to sump from lube oil filter housing on one of mains upon shutdown. Any thoughts on this issue?

Did someone accidently leave one of the handles up inside the oil strainer housing(ice cream tray)? There should be two handles that pull up and turn 90 degrees. One is for removing the strainer for cleaning the other allows for the filter housing to drain back. I don’t think you can close the cover though, if the drain handle is up.

No…handles are down. Right now we’re just baffled. Don’t see any logical way for this to occur. Brand new engines so it’s a mystery. Not even 1000 hours on them yet.

Is there a check valve in the line? Maybe a little piece of something caught in it?

If they are new engines , I would be checking all of the piping maybe someone left the guts out of the check valve.

It seems in our fleet if a boat sits for a week or so it’s normal for the filter to have drained back to the sump. This means two things, it takes longer to prelube and you have to prelube in order to check the oil level prior to start up. I think our filter pots vent to either the oil cooler plumbing or to the bevel gear housing of the governor (I can’t just go look because our EMD boats are so reliable I they never have to come in for service). But without a check valve in the vent line the filter pot will drain back quickly, within a few hours. The oil leaks by the gears in the scavenge pump.

Typically there are no check valves in the oil piping of an EMD engine.

Thinking back, the Filter pots on the EMD Boats that I worked on were mounted so the bottom of the pot was lower that the sump.

I’ve seen several filter configurations over the years. Some low, some high, some horizontal. The last EMDs I worked, around 2000 with were 12-E7Bs with the small pots mounted above the crankcase. They drained back into the sump.

i think manufacturers do this stuff when their engines last too long
Cat 3412’s take forever to get oil pressure

Turned out to be leaking back through the filter housing drain valve in ice cream box. EMD says that it has been known to happen before. The final fix will be to install an isolation valve in the drain line next time the filters are changed out.