Community Forums

Bailee · 02-27-2011, 08:32 AM

I have a 2007 400 ISL cummins engine that is over heating. Cummins has replaced the thermostat and that has not solved the problem.The gauge goes from 1/2 to 3/4 all the time. Any Ideas?

gmanatl · 02-27-2011, 08:46 AM

I had the same problem with my 2008 Winnebago tour with isl 400. Freightliner put it on the computer and it showed my engine had dropped three codes two of which were temperature related. They conferred with fl hq and they said they had seen this before and told the dealer to reflash my computer. This solved the problem and I have had no more issues.

Steve Ownby · 02-27-2011, 06:37 PM

I believe you have a rear radiator. You may just need a very through cleaning of the radiator stack. With a rear radiator this needs to be done annually.

Steve O

newk72 · 03-04-2011, 05:44 AM

I had this problem with our 09 Tour. I am now on my third fan clutch. So far so good on this one. If you would describe your issue in more detail I could compare it to my heating problems.

Bailee · 03-05-2011, 07:51 AM

The gauge goes from 1/2 to 3/4 or 185 degrees to 210-215 then drops to 185 again.

newk72 · 03-05-2011, 03:06 PM

It appears your readings are about normal. When the temp reaches around 210 degrees the fan clutch engages the fan and brings the temp back down to 185. Then the process starts all over again. It is supposed to save some fuel. Under pressure the boiling point is around 230 or higher. Mine was actually going so high it would shut down the engine.

Bailee · 03-06-2011, 06:47 AM

Do you have a rear radiator? Does your gauge still move 1/2 to 3/4. I have spoken to others that tell me their gauge stays at 1/2 all the time a never moves. High outside heat it goes up alittle. What model do you own?

newk72 · 03-06-2011, 07:08 AM

I have the 09 cummings 400hp with the rear radiator. I don't know when they went to this fan clutch set up. It is possible some of the other responders have a positive fan that runs continously.

RVThere · 03-06-2011, 04:38 PM

I second the suggestion to clean your radiator. I did it last summer after a cross country trip where my temps got hot on every uphill climb in Nevada. I could not believe all the debris that was in there. FCCC recommends using Simple Green.

Bailee · 03-07-2011, 06:49 AM

Thanks, What is the best way to do that? Spray the outside with simple green, let sit, then spray with garden hose? Did your gauge move or stay in the middle?

Ronnie Bledsoe 2006 Dutchstar 43' · 03-13-2011, 11:01 AM

You need to get the solution on the inside (engine side) of the radiator and flush it out from the same direction. Oil and debris collects on that side.

zman62 · 03-13-2011, 11:20 AM

With a rear radiator this is a common problem. Oil residue from the breather tube collects on the engine side of the radiator then all the road dirt stick to it. I had the same problem on a previous coach. Once i cleaned the engine side of the radiator it ran cooler than it ever had. Good Luck!!

Bailee · 03-14-2011, 07:34 AM

Thanks, What is the best way to do that. There is very little room to spray it with simple green on the inside. Can I spray it in the rear side ( back side) and run the hose from the back side to the engine side? Let me know.

RVThere · 03-14-2011, 07:41 AM

I put a generous amount of Simple Green on the side you see so that it would soak through the fins. It is definitely challenging to get any Simple Green to get on the other side of the radiator as access is tight. After letting it disolve the gunk, I blasted it with the hose (hot water if possible) and a ton of gunk dropped onto the driveway.