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bpu699 · 10-10-2020, 06:02 PM

Onan 7500 marquis gold diesel... runs great, rebuilt 2 years ago by prior owner when electrical converter failed...

Went to change the oil, had some lumps come out... figured it was sludge...

Looked in the drain oil pan... there were 2 dead wasps and a small caterpillar...

Huh?

Air filter is on... how the hell would that get into the crank case?

Got in during the rebuild? Is there a crankcase vent?

Ran fresh oil, drained again... no more insects...

BrokeDown · 10-10-2020, 06:41 PM

I'm sure that Cummins would not like the idea of a catapiller being in their generator.
-B

Bob_C · 10-10-2020, 06:46 PM

And you found out none can swim.....

arcaguy · 10-10-2020, 06:57 PM

I don't think the air filter would have anything to do with insects in the oil sump. If it does, you've got a hole in a piston or something else terribly wrong. I'm thinking the "caterpillar" was actually a wasp larva, and yes I agree it probably got in there during the rebuilding process. I doubt that wasps like living in a crankcase. I would chalk it up to one of those inexplicable life experiences and move on. If it happens again I would call Ripley's Believe it or Not.

Dutch Star Don · 10-10-2020, 07:28 PM

I think you should call the oil company and tell them there were bugs in your oil, just like someone does when they're in their food. Maybe you'll get some free oil!

It's surprising that the oil pump didn't chew them up. Are you sure they weren't in your drain pan when you started?

dkoldman · 10-10-2020, 07:48 PM

Take a picture of the oil drain line? I suspect the wasp had built a nest in the drain line and not in the actual oil/crankcase itself?

My generator, I have valve to open for oil to drain. I could see a wasp building a next in that line.

sibe · 10-11-2020, 06:15 AM

Quote:

Originally Posted by dkoldman

Take a picture of the oil drain line? I suspect the wasp had built a nest in the drain line and not in the actual oil/crankcase itself?

My generator, I have valve to open for oil to drain. I could see a wasp building a next in that line.

yep makes sense, i looked at few videos and diagrams, there is a drain valve and a hose that hangs down, perfect house for little critters..

bpu699 · 10-11-2020, 07:37 AM

I believe it’s a Kubota motor. There is no oil drain line, plug is on the bottom of the crankcase...

I also wondered if they were in the oil drain pan to start with, but doubt it as it’s just a simple aluminum pan and I saw “stuff” coming out...

Can’t imagine it would hurt anything as usually a sump pick up goes through the oil filter before going further...

But that was weird... and they will well preserved...

YC1 · 10-11-2020, 07:43 AM

Those monsters build everywhere. I keep a can of wasp spray in my sight distance most of the time around here. Pee hole on my boat engine is a favorite. Pulled the lower unit off to rebuild the water pump once. It was fine. Wasp had filled the little tattle tale hole.

I find bugs in my lawn tractor gas tank all the time. The darn things crawl into the fill spout and then get washed into the tank when filling. Amazing they can stand to live in those things.

I am amazed but no longer surprised.

NevadaNick · 10-11-2020, 09:56 AM

They probably got in through the crankcase vent.

bpu699 · 10-11-2020, 01:07 PM

Quote:

Originally Posted by NevadaNick

They probably got in through the crankcase vent.

That’s what I thought but for the life of me I done see one, unless you have to take the entire covering off... usually wasps seem to find openings that are obvious... for example, found a wasps nest also in my black tank vent...

Would be a lot of fun to get bit in my ***

.