Running temperature

[Floridakraut]

2006 Monaco Diplomat with Cummins ISL 8.9 400 HP
Always seemed to have higher than normal running temp (204-212) but have now a new issue
On the return trip thru the mountains of NC I noticed that Weldex onboard computer showed up to 250 degrees and derated the engine to a max of 1350 RPM
I verified that the analog gage of about 206 was correct. How in the heck can I correct the digital temp?
Any help would be greatly appreciated

 

[Fish]

I can tell you what I think I know, which isn't a lot.
Weldex is simply the maker of the monitor and possibly backup and side cameras. The Aladdin system displays the data to your monitor.
Aladdin gets it's info from the cummins ecm and puts it on the screen.

The cummins ecm runs your engine. It will shut it down for low oil/oil pressure/coolant/overheating, a truck mechanic told me you just can't run the motor if something's wrong that might destroy your engine, the ecm shuts it down.

I don't know how you verified the temp but I would trust the ecm readout before the mechanical gauges, I read about people trying to fix the rv mechanical gauges all the time. You can get a mechanic with the right code reader to read the history on the ecm and it will tell you everything that faulted. You were in the mountains, it could have been a coincidence and the problem might have been something else.

Possible overheating solutions, dirty radiator, low coolant, sticking thermostat, fan problems.

 

[Floridakraut]

Thank you so much for getting back to me. I verified the temp with a thermo gun on the lower and upper radiator hose. I brought the Rv to Certified Diesel this morning. They expecting it to be the temp sensor on the recovery tank. I drove almost 400 miles with the warning on the dash “stop engine “ and got home without a problem ( other than the engine was derated) I will let you and the forum know what they find next week. Thanks again for your help. Made a lot of sense

 

[Floridakraut]

Got the bus back. It appears that the thermostat only opened about 70%. The temp sensor on the side of the engine below the thermostat was faulty and the analog temp sensor which strangely is a coach supplied sensor and not Cummins was also not functioning correctly. Engine now running on computer screen at a 186 degrees. Analog gage showing much cooler temps than before but still goes to the 3/4” mark on the gage anybody experiencing the same? I’m used to gage indicators to stay center on gage

 

[Fish]

Got the bus back. It appears that the thermostat only opened about 70%. The temp sensor on the side of the engine below the thermostat was faulty and the analog temp sensor which strangely is a coach supplied sensor and not Cummins was also not functioning correctly. Engine now running on computer screen at a 186 degrees. Analog gage showing much cooler temps than before but still goes to the 3/4” mark on the gage anybody experiencing the same? I’m used to gage indicators to stay center on gage

Going by memory I think my temp gauge usually stays above the halfway point when warmed up and going down the road, 5/8 let's say.

 

[Floridakraut]

Thanks for the reply. I would feel much more comfortable if this would be the case in my gage. Gage bad??
Not sure how that can be checked. Temp gage is part and included in speedometer and transmission temp (3 gage set up in one). Would be hundreds of $ to even attempt to get one, if I can even find one