What is needed for Onan 5.0 generator oil change tune up

[chickensofthesea]

I can't find a list of the filters or things needed to change the generator oil on a Onan generator. Its starting to shut down after running a while and is about due for oil change. Any advice on which parts to use for this would be appreciated. Any other generator maintenance suggestions or checks to do while our guy is in there would also be helpful.

 

[it4llc]

We've got a NextGen, but when ours was quitting after running a bit, it turned out to be the impeller starting to come apart.

 

[HopTug]

I just happen keep a note on my phone with all the regular maintenance I need for winterizing!

Cummins/Onan 5 kw Generator (MDKBH)
- Oil Filter: Cummins 185-7444
- Fuel Prefilter: Racor R11T
- Fuel Filter: Cummins A026K278
- Impeller: Sherwood 08000k
- Oil: 15w40

With regard to the shutting down, I’d make sure the raw water filter is clean and run barnacle buster through the system. Could also try backflushing the water intake.

Hope this helps!

 

[bradf]

I just did the initial engine break-in oil change on our R-31 Onan 5KW MDKBH genset. It's an easy DIY job. The needed parts are printed on a placard on top of the unit. See your owner's manual for recommended oil and coolant specs.

StrangerDejaVu got it right. The only thing I would add is that if you want to order the Cummins original part impeller you need the "impeller kit" p/n 541-1524 which includes the impeller and o-ring gasket.

The engine oil MUST BE a CH-4 (minimum) formulated heavy duty oil for diesel engines. The letter after the C must be H or greater, higher letters are better. SAE 15-40w is the correct oil weight. I used a CJ-4 15-40w oil that I got from West Marine.

I ordered the parts directly from Cummins online (I like to have spares on board). I also ordered their pre-mix 50-50 coolant, Fleetguard ES Compleat EG Premix 50/50 aka "Cummins Blue". Any ASTM D6210 standard glycol coolant should be OK.



 

[Thorolson]

With regard to draining oil, I recommend making a fitting which allows you to drain the oil from the drain. On our 2012 R29 it is easy to remove the left side of the generator sound shield to access the drain fitting and I made a 90° fitting. I have a picture in my photo album.

 

[chickensofthesea]

Thank you for all of this information! I will relay it all to my husband and he will be happy to have his air conditioner back!!