Cummins Onan generator

[gpci]

2023 Georgetown 378 XL

My Oman qg 5500 generator failed me this past weekend , yes oil level and velocity is good , I change oil before recommend hrs always , unit was hot and smoking after running for 2 hrs ( 90 degree weather outside)
And now she’s trying to auto start without me touching start button, but won’t run , (yes plenty of gas too) so I disconnected the power wire at the generator terminal till I figure out what’s happening. Any help from my camping family would be appreciated

[NXR]

OK, you win the contest for the newest motorhome.

After a drive with a dealer tech on a hot day my 5500 shut down as we turned into the dealership and then kept trying to restart itself. I held the Stop button on the touchscreen and it stopped trying to restart.

We opened the compartment door for the generator and got hit by a massive blast of heat. I opened the compartment on the other side and got hit by a massive blast of heat.

The tech tried to remove the Onan cover but it was too hot to touch. And I didn't think to grab my infrared temperature gun.

Nothing was ever found and there were no codes. That was the only time it happened and we've been in a lot hotter temps. It felt like the undercarriage heat from the exhaust just built up once we slowed down and caused an overtemp shutdown or the fuel to vaporize in the lines.

Ray

[Dodge Guy]

Sounds like the issue with mine. Mine will die when it's hot (on the highway for hours and outside Temp over 85deg) and you hit a very harsh dip or bump or if you turn into a driveway and the RV rocks hard! It always starts right back up. I too can feel the heat coming out of the inside of the generator. It's not an oil issue. I'm thinking the fuel pump is slowing down when hot and the float bowl isn't staying full. When it acts up I can give the generator a Hard use and it attempts to die out.

BTW, my generator thread is in the general MH section.

[gpci]

I appreciate the help , I currently have the positive cable feed to the generator disconnected , if I connect it it tries to start itself without touching either start button
And still won’t start anyway, I’ve tried disconnecting each switch one at a time to see if the switches were a problem, no change . Good news is I now know more about generators then I ever wanted too lol
Tks again

[centurion493]

On Friday last week, went through Needles Calif on the way back home to the OC from NM. OAT sitting at 114 F. While in motion, Gen on and running the interior AC units to help cool the coach because as we all know, the chassis AC can not keep up with that amount of heat and can not be expected to keep up. All fine and good until we stopped to top off the gas before getting back into Cal and much higher fuel costs. After filling it up, started to get back on I40 westbound and the Gen shut down and took the AC in the coach with it. Despite our best efforts to restart the Gen, new BTW and without issue until then, it would not start again. The precision plex panel simply flashed start/stop in red repeatedly. I assumed it was a overheat protection feature and thought that as we drove it would cool enough to start back up. No dice. The OAT remained tripe digits until well into Riverside and the flashing start/stop on the panel continued and the gen would not start. Not until back in OC, with temps in the mid 90's would the gen start back up. Tried it numerous times since then and it runs with no issues. I was unable to find anything about the start/stop flashing meaning within the manual for the gen or precision plex unit. Had to have been the heat and a preventative shut down....I hope....

[gpci]

Sorry nxr typo 2013 correct year

[gpci]

For centurion,
I installed a air grabber vent on my generator door to help cool around the generator while it’s on when driving , this helped , but I have not been in 100 degree plus weather yet .
See picture :
you can buy them at most boat supply stores or on line but they are made for boats ,
It’s unfortunate that our generators aren’t water cooled

[Dodge Guy]

That's what I've been looki for.

[centurion493]

Looks like a good idea but a quick question....Are the scoops pointed forward or towards the back. If forward, any issues with rain/puddle splash etc... getting scooped into the compartment? The gen is self contained within the compartment but the compartment itself is pretty open on all sides except for the metal frame mounting for the gen.

[Georgetown377]

Since the issues are happening while in hot weather. Could it be the the air cooling the generator that comes from underneath is very hot or hotter with the heat coming off the hot asphalt.? Or maybe it just can’t grab enough cool air as the RV is going down hot highway.

[Dodge Guy]

I personally belive it's a combination of both!

[gpci]

The scoops facing foward to grab air and force it into the generator area , i place mine towards towards the front of the hatch door for maximum performance , I bought 2 and used the second one to finish inside the door , but cut off the scoops on the inside one so it looks nice ( door is thick )
Make sure to tape area you are cutting through so paint doesn’t chip and remember there is syrofoam inside the panel
Good luck