At my workplace we have an emergency generator unit. The engine is a V12 turbo-intercooled Cummins, oil capacity w/filters about 24 gallons. A few days ago the outside air intake and the radiator louvers failed to open causing the engine to overheat after running about 30 minutes. Mercifully the safety circuits kicked in and shut it down avoiding any damage.
Now here's my question. Upon checking the oil level after shutdown it barely showed on the dipstick. Eight hours later it still showed probably five gallons low. The next day all oil was back in place and looked and smelled new. Where did the oil disappear to ? We have since ran the unit under load 3 hours and all is normal- and 15 minutes after running the oil level is as it should be. Sorry for writing a book but nobody here knows engines well enough. Thanks.

sounds like time to chnage the oil. I am not that familure withthe V12 cummins but a lot of oil will stay uptop on V motors for a few minutes usualy but again not that familure with the Cummins V motors.

OH I say time to change it couse it should drop faster than your did and that usualy means its gotten to thick and doesnt have the correct viscosity any more.

Tell them to quit parking that gen set on a hill every other time they check the oil.
Seriously, that's a new one. I'll ask around.

Ain't got a clue. Sometimes in deals like this a good place to look is the dipstick. Is there any way it or its tube viberated to a position that would give false readings? the stick probably has the capability to be read with the engine running, to check levels without shutting it down, are we sure we were reading it right??

On a logging job once, I had to argue my behind off to convience the mechanic that the Cummins Skidder I was operating had two thermostats, one on each bank. It was cold, and it would hardly run, he check one thermostat and it was okay, and when I finally hounded him to check the other side, it wasn't even there. go figure.

Not accusing anybody of being less then brilliant, but from past experiences sometimes its the obivious that stumps.