Oily discharge in generator exhaust

[MV Wanderlust]

An acquaintance three slips down recently changed the oil in his genset. He admits he put in a little too much oil when he refilled it. Ever since then, when he starts the generator, there is a very thin film of what appears to be a petroleum-based substance mixed in with the discharge from his generator exhaust. He also says there is an "oily smell" after he shuts off the generator. We kind of got in a little argument about it but I think both symptoms are related and they're just because the oil capacity is over full. He thinks it's a much worse problem but there are no other symptoms. I think if he changes the oil again and this time is careful about how much goes back in, he'll probably be fine. Anyone care to weigh in?

[capngeo]

Or....... just remove a little oil

[a64pilot]

Or wait until it blows out a seal, then he will be correct.
Often if you have too much oil, the oil gets beaten into foam, that doesn't lubricate very well and can build excessive back pressure, usually excess oil goes out through the crankcase vent making it burn oil.


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[valhalla360]

Step 1: Remove the excess oil.

[ctl411]

Step #2 try injector cleaner. Had similar issues with my genset this spring. Used a full strength dose of cleaner as a easy fix. Worked, I lucked out didn't have to pull injectors. Side benefit main seems to run better also.

[MV Wanderlust]

Thanks everyone. I'll pass on the recommendations. Then it's up to him.

[CaptTom]

Originally Posted by ctl411

Step #2 try injector cleaner. Had similar issues with my genset this spring. Used a full strength dose of cleaner as a easy fix. Worked, I lucked out didn't have to pull injectors. Side benefit main seems to run better also.

My mains are smoking a little, and I was thinking of pulling the injectors for cleaning this winter. With 12 of them, that's going to be quite a project.

Tell me more about the liquid cleaner. Do you think just putting a dose into the Racors would do it? How much?

[a64pilot]

If you want to go with a cleaner, try either Sea Foam or my favorite Techron.
Techron first came out in the late 70's I think and at the time I had a three cylinder John Deere backhoe with an injector clogged so bad it would idle on two. I tried the Techron cause the local Chevron Jobber gave it to me. It actually worked.
Now you need to remove them, cause unless you have them tested you won't know if the tips are worn enough to justify replacement, but Techron will clean varnish off of one.

[ctl411]

Can't recall the cleaner name. It was a "booster/cleaner. You could rig up a small fuel jug to try instead of your I assume big main tank.

[a64pilot]

Old, old school way was a quart of automatic transmission fluid per 10 to 20 gls of fuel.
Hurts nothing and the tranny fluid is high in detergent

[hydrodane]

AT FLUID ? Isn't that asking for trouble with possible seal damage? I've seen it happen. Even diluted, the stuff is quite corrosive to seals, particularly aged seals.

I've used techron for injector cleaning as a regular basis maintenance on a 19 year old Chevy 5.7 vortec with OEM spider injectors. About every fifth fillup. Has never failed. (But yes, the upper manifold gasket failed, but caused separately by poor OEM design of gasket material and poor chemistry design of dextron GM coolant.

I'm certain similar comparisons can be made with marine applications.

I personally would not recommend AT FLUID in fuel.

[a64pilot]

Automatic transmission fluid is not much more but I believe 5W oil with a lot of detergents, people have used it to flush out oil pans in old motors and to clean Diesel injectors for Decades.
An automatic transmission is a hydraulically operated thing, full of seals and O-rings. ATF won't eat seals.

[Kita]

That's true atf in small amount won't hurt anything,old truck driver would put in a quart to his tank & tank was 100 gallons I think,told me it helps keep it clean

[Kita]

That Genset is definitely over full of oil, excess oil goes out the PCV & that extra will for sure go out the ex & will make it run wacky also but probably won't hurt anything, just run like crap & smoke & if it goes long enough might even plug the muffler

[Redpcx]

ATF is mostly low viscosity lubricating oil. While it can be a good, mild parts cleaner, it is not as strong a solvent as diesel fuel. It doesn't smell as much as diesel, which is a reason to use it to scrub machinery parts. It will burn with a lot of energy, so your engine won't run bad if you put a low percentage in your fuel tank. Clean your injectors? Only if you buy it from ME! Just kidding, it has no volatile solvents that will clean your injectors. Buy injector cleaner.
If the oil sump if overfilled to,the point the crankshaft touches the oil, the resulting foam can be sucked from the crankcase into,the breather, and some may burn. The engine can also runaway, run at high speed and cause lots of problems. Run fast, blow oil out the exhaust , and NOT shut down even if you shut off the diesel! I've seen it, and it can be pretty exciting. Just check the oil level. If it is higher than the full line, drain some before starting the engine. Severe damage can result from overfilling
In theory, you could get enough oil in the cylinder to lock up the engine.