Generator Oil Change (how to)

[MWARREN]

I have a 2011 Itasca Impulse 31J. It came with the 4000 Onan/Cummings generator. I have not had it long and I have no clue how many hours are on the oil. I have no idea how to change the oil or for that matter how to check the oil level. Anyone have good directions for this process?

[Winterbagoal]

Didja try an internet search for "onan cummins 4000 generator" ???
I got several "how to/oil change" youtube vids as hits.
Always remember, Google is your friend.

[TJFogelberg]

I'm an accountant by trade so very low mechanical skills but I figured out how to do it myself. My first surprise was that there is no filter to change. You need a Torx Bit Socket T-30 to remove the screw on the cover under the motorhome to access the nut to the generator to drain the oil. Have a plastic pan handy to catch the used oil. Use a 1/2" Socket to remove the nut. Start the generator before changing and run for 5 minutes. Then wait 10 minutes to change. Open valve on generator to allow air flow.Don't over tighten nut when replacing. Wear gloves and googles. Once you do it, only takes 10 minutes after the cool down period from start to finish. Saves a visit to dealer. I couldn't believe their posted price to change out the oil in my Onan generator...$169.

[creativepart]

Yes, YouTube has many videos on Onan service. BUT! Be aware that the procedure for the 4000 is different from other models... even the 5500.

So, be sure you are following the instructions for YOUR generator.

Here’s a video for the 4000:

https://www.youtube.com/watch?v=9kdEUXoYdfU

[Goodspike]

Originally Posted by TJFogelberg

I'm an accountant by trade so very low mechanical skills but I figured out how to do it myself. My first surprise was that there is no filter to change.

Odd, I was just thinking about that in a different context. Small engines don't tend to have oil filters. That makes sense when you're talking about maybe a lawnmower engine where the deck will likely rust through before the engine wears out. Briggs and Stratton even have some engines now where they don't specify oil changes. I have one of those engines and change it anyway.

But at some point an engine becomes valuable/expensive enough that it's worth protecting with an oil filter. I'm surprised a motorhome generator doesn't fall into that category. I'm not surprised my small under $500 portable generator doesn't have an oil filter (the device I was just thinking about).

BTW, there almost certainly is an air filter to change, so you should check that out.