We have a Onan 5500 generator in our rig that doesn't want to run more than about 10 minutes when we are driving. When parked, it runs until I shut it off. The unit only has about 28 hours which is not a lot, so the first owners didn't run it much. I changed the oil and filter the other day & thought that might help. I am able to restart after a few minutes, but it will still shut down when rolling down the road. I do have a full fuel tank & the altitude adjustment is set for sea level where we are now. I have the manual and I need to verify what code is blinking, but I don't understand what would be different about driving and sitting still. Fluids being tossed around? Any thoughts?

Double check the oil level once again. They have a switch to shut down when oil is low. Turning a corner will likely cause them to shut down when low alos...

My 5500 Onan was doing about same thing. Has been several posts on issue. Mine threw code 36. Fuel pump was over heating. They replaced under warranty. So far runs ok. If it happens again I am going to move the fuel pump away from the generator a few feet and bolt it to the MH frame where it will get more cooling.

The code is 36 which seems unspecified stopping. Not much help. I parked too close to the pedistal to open the door to check the oil. Have to wait until I move now.

Jack&Kay wrote:The code is 36 which seems unspecified stopping. Not much help. I parked too close to the pedistal to open the door to check the oil. Have to wait until I move now.I'm betting your oil is OK. Onan repair said you can feel the fuel pump chatter as it heats up. There have been several posts about the same problem about the 1st week of July.

I just don't understand why it will run ok sitting still, if that's the case.

Onan 5500 Generator stops | Good Sam Community

TEXAS
Explorer
Aug 16, 2013
Before you go to a shop. Check your oil again. If you can't smell the gas put a small amount in a container. Try lighting it with a match. If it lights. You need to change the spark plugs and oil and filter.
haddy1
Explorer
Aug 16, 2013
This is a long shot but it happened to me about 20 years ago. My generator (Onan 4KW) would run fine when stationary but shut down while moving (much like the OP). I found that a nut had come off one of the terminals and would short out intermittently causing the generator to shut down.
Jack_Kay
Explorer
Aug 16, 2013
TEXAS wrote:
Did the oil smell like gas. If the oil level was ok. After you added oil and now runs over. You are getting gas in the oil.Most likely running on one cylinder.

I don't think it did. I'm now thinking I need to find an Onan shop or whatever to take a look at it.
Jack_Kay
Explorer
Aug 16, 2013
jsimons3 wrote:
Take a close look at your air filter.....it might have collapsed or
needs changing... my Onan was doing the same and mine was the filter
that was coming apart.

Filter looked good, I checked it.
jsimons3
Explorer
Aug 16, 2013
Take a close look at your air filter.....it might have collapsed or
needs changing... my Onan was doing the same and mine was the filter
that was coming apart.
TEXAS
Explorer
Aug 16, 2013
Did the oil smell like gas. If the oil level was ok. After you added oil and now runs over. You are getting gas in the oil.Most likely running on one cylinder.
Jack_Kay
Explorer
Aug 16, 2013
It's an Onan Marques, (sp) 5500. Don't know what the serial number is. Well I managed to add oil, but it shut down several times, while driving with error code 36. When I got home and took the oil fill cap off, oil ran out. I decided I must have over filled it. I drained about a pint out and will try it again tomorrow.
TEXAS
Explorer
Aug 14, 2013
Again need to know what you have. Full model and serial number.You could have a low oil level switch. Which is bouncing around when driving. Giving you a false shutdown,or you could have a pressure switch. When you are parked it takes away the stress and vibration of the road.
Jack_Kay
Explorer
Aug 13, 2013
I just don't understand why it will run ok sitting still, if that's the case.
WyoTraveler
Explorer
Aug 13, 2013
Jack&Kay wrote:
The code is 36 which seems unspecified stopping. Not much help. I parked too close to the pedistal to open the door to check the oil. Have to wait until I move now.

I'm betting your oil is OK. Onan repair said you can feel the fuel pump chatter as it heats up. There have been several posts about the same problem about the 1st week of July.

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