[Jeff]

Mine has oil pressure and water temp safety switches so I assume all of them have these.

The switch for the water temp may be bad.

If you are sure the gen is not over heating take the wires off the switch for the water temp and connect them together and if it runs longer maybe when the switch heats up it loses contact internally.

If the water is circulating through the radiator correctly that indicates the water pump is working, I guess.

[Bryan]

Buddy. I revised an omission in my post to clarify that I do on fact believe the temp gauge and sesor are not malfunctioning.

I have also cut pressure relief slots in my long generator exaust in case the pinched exhsust pipes (from road debris) possibly was causing the over heating..

[AL]

Jeff, where is your radiator located? Mine was quite stupidly placed in the engine compartment, so on a hot day it was pulling 200 degree air through it. It would overheat after about an hour or two on the road. I had to add louvers to the compartment door and create some ducting to suck in cool air.

Also check that your radiator fan is turning the correct direction. Those electric fans sometimes get reversed.

[Doug]

Have you been able to check the radiator supply and return pipes/hoses for obstruction? My bus has the radiator behind the front bumper while the genny is all the way aft bay pass side. Could they possibly make a longer run for cooling?

[Dick]

Does the Gen shut down after the time you stated????

[Chas]

Has someone replaced any of the coolant hoses ?

Coolant hoses on the suction side MUST have wire either in the hose make up or inside the tunnel of the hose. Without support hose can reduce flow which usually one of the inside layers separated that you cannot see…causing a restriction.

AL

[Doug]

Use an IR temp gun(harbor freight) to get temps at various locations, especially where temp sensor is located, to see if its really over heating.

[Alvie]

What’s the make/model of the gen on your coach and are you SURE it’s overheating. I had a shutdown problem on mine due to voltage regulator. Also could be fuel related.

[Archived]

Has the bus been stored for a while? How old is the fuel? If the fuel is real old and filters have not been changed, it could be starving for fuel??? Just a WAG on my part.

[Deleted User]

If you are losing coolant out of the radiator over flow it is probably your head gasket. My Gen would run about that long and then go down on high temp after it puked coolant out. Replaced head gasket and all is good.

[Jim/Chris]

could you be getting air in the fuel supply? there is a petcock wing nut on the fuel line that will allow some of the fuel entering to go straight to the return line. If it is all the way closed and you are sucking in air, you could run for a period of time and then it will shut down due to too much air building up in the system. If you keep that petcock wing nut open just a half a turn it will general bleed itself of air.

[Peter]

If I read the Koehler manual correctly, it says change hoses annually. But I can’t believe you would have to change the radiator hose annually. Don’t know if mine have ever been changed, but they still look in good condition.

[Archived]

Hey Jeff,

all these people took time to help you? Did you get it fixed? Did you see the answers? Let us know!

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[Tom]

My apology to everyone that chimed in for the late thank you but I’ve been offline with no hot spot where I was camped. I special thanks to joelselman (no name listed I byline) for suggesting the voltage regulator which I found implausible but there it was (apparently and knock on wood). I’d had multiple generator issued the last 8 weeks. I will be pleasantly surprised if they are finally over but I have this sneaky suspicion that I’ll be posting again about this, or another, issue.

It was the voltage regulator somehow malfunctioning after warming from the ambient heat in the generator bay. I knew for a fact that that the generator was overheating and somewhere along the line I solved the real overheating issue and the baton was passed to the phantom overheating problem from the voltage regulator. My temp gauge was showing overheating and the generator was shutting down. I swapped out the voltage regulator and it’s ran fine today for 8 hours so unless I just got lucky, I think I found it but I would not be surprised if I wind up posting again to say that the issue resurfaced because I have not had a moments peace from the generator I the last 6 weeks. Hopefully it’s solved. Thank you again for all the help.

[Peter]

I had a Royale that would do the same thing and it was the voltage regulator also !!!