Apwel3209
So here’s the scenario. A guy from the company I work for performed general maintenance on a 14kw Generac about 3 weeks ago. He changed the oil, oil filter, spark plugs, and air filter. Then a week later the customer called back saying the generator had been running for a while when they had utility power so I went and determined it was a bad controller that was blowing the n1,n2 fuses and we replaced it. 3 days later they called again saying there was oil everywhere and the oil cap was on the ground (which it was not when I was there last) so we went back cleaned it up and filled it and it ran fine. The next day oil leaked out again (when it was off) and I noticed oil under the air filter but I can’t see any leaks in any obvious places anywhere. Any ideas as to where/why the leak started?
model# 0062410
serial# 8377963
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78buckshot
I would say the oil cap was not threaded correctly or was not tight enough after the oil/filter change, after the first clean-up the remaining oil that you could not get to drained out of the engine shroud and other hiding places, it will take a number of clean-ups to get things back to normal.
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BrianMartin
78buckshot wrote:
I would say the oil cap was not threaded correctly or was not tight enough after the oil/filter change, after the first clean-up the remaining oil that you could not get to drained out of the engine shroud and other hiding places, it will take a number of clean-ups to get things back to normal.



Exactly.. You're going to be seeing oil for a while. Running it will help the oil warm up and drip down faster. 
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Peddler
Is it possible that the engine was overfilled when you guy did the oil change?  I agree with what was posted that residual oil would continue to come out especially as it got hot.  I have also see units push oil into the air box, saturate the filter and then pull heavy vacuum on the crankcase which causes further oil saturation of the air cleaner.  Probably just an error on the original oil changer.
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Apwel3209
The residual oil makes sense so that could be some of it, but When I checked after he had cleaned it up and filled it again the oil level was below the fill line again (basically the bottom of the dip stick)  so I don’t think it’s strictly residual unless the other guy has no idea how to read an oil stick. If it was over filled it could create a higher pressure but has anyone seen a cap blow off from pressure and if so is this engine ruined or is it a simple drain and refill with a new oil filter again? Because the other guy is telling me he filled it and it ran fine.
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BrianMartin
Pretty unlikely high oil pressure would blow that cap off, there are easier paths for the pressure to take (unless the cap was very loose). If it were overfilled it would have likely been exhausting a fair amount of smoke.
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Peddler
Over fill could push a seal out.
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78buckshot
Oil pressure does NOT pressurize the crankcase, it pressurizes the space(clearance) between the main bearings and their journals and the rod bearings and their journals. The oil then spays out of the clearance and aids in lubricating the cylinder walls, wrist pin, cam lobes, cam gears and the oil mist makes it's way to the overhead valve train, so overfilling will not increase the oil pressure and COULD reduce pressure due to foaming. The crankcase breather system is in place to keep from pressurizing the crankcase and will normally produce a slight vacuum within the case. Overfill can cause air filter and air box contamination as stated. If in fact the engine is losing oil or using oil then you have other areas to check. Do you know if the valve lash has been checked and adjusted?
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Apwel3209
It’s written on the valve cover that they were adjusted at 66h it’s currently at 90h but the valve adjustment was not done by us. 
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Canada_Guy
Here's an interesting video about oil in the cabinet. It only occurs during very cold temperature and is due to oil collecting in the air filter box, freezing and blocking the "exhaust" port therefore pressurizing the block. This might explain some occurrences of oil in the cabinet.

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Ron Goldstein Rongold
VERY informative video. I'll have to go and check mine tomorrow !!!


RON
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BrianMartin
I've never seen that problem before. I must not have the weather for it here.
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Wireform

Was just looking at this YouTube and very interesting to say the least . I was thinking of a remedy to the problem. Not familiar with this air box and don't know if there is another opening there that would interfere with the following. There seems to be enough space between the problem port and the underside of the air filter to fit some kind of 90 degree fitting or two of them and bring the port opening higher up to avoid or better said, prolong this issue. Sort of a longer time frame before it would catch you off guard.

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nrp3
Is this what the breather heater is supposed to prevent?
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Cobranut
First off, the exhaust ports are in the heads.
What you're referring to is the crankcase breather.  It allows blowby vapors to vent from the crankcase and be recycled to the intake and be burned by the engine.
The best fix, though not legal from an emissions standpoint is to reroute the breather via a hose out the bottom of the enclosure, and plug the hole in the air cleaner.
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