Originally Posted by LS-one
I've done my own oil changes my whole life without a hitch, but this one is baffling me. I changed the oil in the generator prior to a cross country trip in January. Went from California to the Keyes down I 10 back I 40. We used the Generator about 75 hours with no issues. Suddenly I stated for a quick use of the microwave and it shutdown. I restarted it and it shutdown again, went outside and oil was everywhere. When we got to next RV park I went underneath and it was coming from the oil filter. Assuming I didn't tighten it sufficiently I bought a new one and did an oil change. All was good until we got home. I ran it last week prior to this trip for an hour and a half all was good. Yesterday the same problem. It was tight so I guess a gasket issue? Looking for ideas.
I had the same problem a year ago with my QD8000. I was just as baffled as you. I double-checked to make sure the old gasket wasn't still in place when I tightened the new filter and gasket. Wasn't it. Checked the new gasket for condition and placement. Wasn't it. Cleaned and checked the mating surface on the generator. Wasn't it.
I have changed the oil and filters on every car, truck, motorscooter, motorcycle and airplane I have ever owned since I was in Junior High. My Dad was a mechanic and he taught me how to do it properly emphasizing not to over tighten and to always do a leak check under pressure with warm oil.
The first time I changed the oil on the Onan I was cussing the guy before me who over tightened the filter. I had to drive a long screwdriver through the filter to get it off. I used the recommended technique for tightening the filter and did a leak check for just a few minutes without warming up the oil.
I ran the generator for a few hours that evening before shutting it down. The next morning I started it up and it ran for a few seconds before shutting down. Without thinking I started it up again and it did the same thing. It then dawned on me to check the codes. After I dug out the manual I saw it had shut down for low oil pressure.
I walked out, looked under the coach and saw a huge puddle of oil on the asphalt. It sure looked like more than 3 quarts. I had to haul a lot of heavy sand from the adjacent dry lake bed to soak it up.
Apparently the Onan builds up higher pressure in the crankcase than most engines and you really have to tighten the filter more than we have all been taught. The guy I was cussing out just did what he had to do.