2018 Mule SX Oil issue [Archive] - Kawasaki Motorcycle Forums

2018 Mule SX Oil issue

01-27-2019, 11:05 AM
My mule has 50 hours on it and the oil filler cap keeps popping off and spewing oil all over the engine. Help.

01-29-2019, 10:58 AM
Ok, I assume you have inspected the cap and its seat carefully to make sure they are not the cause.

If they are ok, then you must have excessive pressure in the crankcase. Is it possible you have overfilled the oil?
Check your PCV and any other crankcase breather hoses to make sure they are operating normally.

But with only 50 hours, is not still under warranty? If so have your dealer check it out.

01-29-2019, 12:00 PM
yeah, Thanks. I checked oil cap thinking I didn't push it down good enough but it is still under warranty so yes I'm thinking I should bring it in.

01-30-2019, 11:52 AM
A Kawasaki mechanic told me it is the oil pressure relief valve hose. He said it is a common problem. It gets moisture in it and then it freezes and the pressure will find a place to go so it pops off the oil cap. Spewing oil everywhere.
I would think Kawasaki would remedy this. Now its just a matter of locating it. He told me but I'll have to call him back cause I'm still not sure where to find the hose.

02-28-2019, 11:14 AM
Apparently is is not a warranty issue. Instead of a update they call it a upgrade. Therefore I paid for it. I just have to crawl under the machine and drain the reservoir when I see fluid builds up.

03-23-2019, 10:57 AM
I have a 2018 mule sx and I'm surprised no one ever addressed this issue. It is a common problem that the pressure relief hose that redirects the emissions back to the engine freezes inside because of moisture build up then pops off the oil cap send oil all over the place. I had a authorized Kawasaki dealer put a upgrade in the line and now I have no problem. The only inconvenient I have now is I have to pull the little reservoir off and drain the water(below freezing). Every brand has their quirks. Is this a Kawasaki thing or is it common for a lot of side by sides?

03-26-2019, 04:08 PM
Glad to hear you got it sorted.

I have owned a 2007 Kawi Brute Force 650 for 10 years and now own a 2018 Brute Force 750. Neither has ever given me any problems at all, and I do lots of cold winter driving. So it sounds like its a Mule problem. Too bad it was not under warranty. You could try writing to Kawasaki to complain.