Onan Oil Mystery Water

Well, I guess I'm surprised that rain water can so easily flow from the outside of the engine to the crankcase via the cylinders. But apparently that is perfectly reasonable.

Normally the generator is under a raintight leanto but that was removed for access for the painters, and then subsequently the heavens poured multiple inches of rain onto us.

The water entry was probably though the air cleaner - it's open all around since being under the leanto meant it was not exposed to weather (until the painter episode).. Maybe I'll find a Tupperware container and adapt it as a shield in case this happens again.

Now that I've changed the oil and filter I'll run it for a couple of hours to emulsify as much water as I can then re-change the oil and filter.

Thanks all for the information!

Stu
 
If you flush the engine with straight Diesel fuel it will clean out any lingering grunge. You will need to replace the filter afterwards. Diesel fuel is a good lubricant and as long as you don't run under a heavy load 10-15 minutes is all it takes.
I'll second all those suggesting intake or exhaust, I remember a steerer parking a D-8 next to a shed years ago and the flapper was stuck open, there was also the down-pipe he had knocked off when parking. It hammered down for a few days and then everything sat while the area drained.
When steerer engaged the donkey the engine fired on a couple of cylinders and we heard the bang about 1/4 mile away.
Not a pretty sight.
 
Good thought on the Diesel flush - I may do that before putting fresh oil and filter in.

Thanks for that
 
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NortonDommi said:
If you flush the engine with straight Diesel fuel it will clean out any lingering grunge. You will need to replace the filter afterwards. Diesel fuel is a good lubricant and as long as you don't run under a heavy load 10-15 minutes is all it takes.
I'll second all those suggesting intake or exhaust, I remember a steerer parking a D-8 next to a shed years ago and the flapper was stuck open, there was also the down-pipe he had knocked off when parking. It hammered down for a few days and then everything sat while the area drained.
When steerer engaged the donkey the engine fired on a couple of cylinders and we heard the bang about 1/4 mile away.
Not a pretty sight.
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So did the crank shaft get mangled or was the Bang the remaining cylinders blowing apart?
 
Bent crank, rods bent and caps twisted off, heads lifted and cracked and a hole punched through the side of block that is off the top of the memory. We figured it had fired on two cylinders at least, this was a long time ago but I seem to remember it was just the front three cylinders that copped most of the damage. Engine was scrapped.
Steerer lost his job.
 
Thats the kind of damage Ive seen from running engines with diesel fuel in the oil. 53 and 71 GMs in particular,the fuel jumpers crack if they are reused and overtightened,and bang-o as a rod comes out thru the block.
 
john.k said:
Thats the kind of damage Ive seen from running engines with diesel fuel in the oil. 53 and 71 GMs in particular,the fuel jumpers crack if they are reused and overtightened,and bang-o as a rod comes out thru the block.
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Diesel fuel in the oil! Im thinking the damage caused from this mixture was a result of an Explosion much larger then a normal Combustion cycle more so then from being hydro locked? Im sure large amounts of ANY fluid inside a motors crank case would cause that type of hydro lock damage like water can do but this seems like it could potentially have been Much more force in your scenario.
 
I could see using diesel to clean a crankcase out but I don’t know about running the engine at least for a extended period of time. Ive used sea foam to clean a engine and if one reads the directions it says it removes water from fuels and oils. Idk if it attaches to the water and burns off or what? It is also flammable
 
Cadillac[COLOR=#000000] I have been flushing engines of all sorts for over 40 years with Diesel, never had a problem and recovered many that were considered write-offs needing a rebuild by others. Basically it cleans out a lot of gum and varnish on old engines, Diesel fuel is an oil,(why C.I. engines are known as oil engines),and a pretty good lubricant, it also removes water from the oil galleries of engines that have been under water or have had a leaking head gasket. I did about 60 vehicles in a week for a dealer that had been flooded in a small town, Groomers cleaned and detailed them all and they were steamcleaned, undersealed and waxed. Full disclosure to buyers and zero problems. Water in the intake on a hot engine is another trick to clean out the crud.[/COLOR] although I have seen mufflers choked with all the Carbon that is blown out.
Procedure is warm engine, drop oil. Replace drain plug, fill with Diesel to fill line, start and run for 5 -10 minutes with a few rev rises then stop, drain, replace oil filter, replace drain plug, fill with new oil and ready to go.
Water injection: Hot engine hold revs at 1000 plus for most small engines, squirt water into intake and blip throttle occasionally. Crap will fly out of the exhaust. Water injection is used on very heavily supercharged engines under load to smooth combustion and increase cylinder pressure while also stopping detonation. Ever notice how on a foggy morning your engine runs better down in a hollow? Nice cool wet air is why.
Big difference between fuel in oil,(leak), water in oil,(leak), and a situation that causes hydraulicing.
 
Cadillac said:
I could see using diesel to clean a crankcase out but I don’t know about running the engine at least for a extended period of time. Ive used sea foam to clean a engine and if one reads the directions it says it removes water from fuels and oils. Idk if it attaches to the water and burns off or what? It is also flammable
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I would VOTE for the SEAFOAM, I have used it for years when I had my engine shop. After IRMA hit our local in 2017 I used gallons flushing engines. Drain the crankcase, new oil &filter plus a bottle of seafoam, start it up & run 5-10 minutes. Drain it, another new filter, new oil, seafoam & run again, then check the condition of the oil, if it looks good run it for an hour or so "get it hot". I would then change the oil again just to be sure. It will not hurt to add some seafoam at every oil change as an insurance policy it will help to keep the engine clean control condensation. when you "monthly test run" be sure she gets good & hot to boil off the impurities. just my two cents
 
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