Where is the normal position for the temp needle? Mine runs on the warm side of the mid-range once underway at hwy speed. Not near the red zone, but just wondering what normal is.
We have a 275hp ISB. It runs at 183F but will cycle to 194-`95 before the thermostat opens and it comes back to 183. I would never know any of that because my normal temperature gauge doesn't move while all of this is happening. We have VMSpc and can monitor digitally and more accurate the temperature. Additionally, VMSpc allows me to see the Intake Manifold temperature. Frankly, I'm more concerned about that.
I have a 260HP ISB and my VMSpc readout is my only way to know my coolant temp as well as many other parameters. My coolant temps vary from 180 where the thermostat seems to begin to open up to less than 190 degrees. The thermostat opening seems to be proportional to temperature and I see no cycling up and down due to the thermostat opening and closing. The Freightliner dash temp gauge is just about worthless in my opinion, no matter how great the rest of the chassis is.
We have the same engine(300 hp) and ours runs right at 200 degrees, has sense new.. It may go alittle above when we are in hotter weather with high humidity..
2003 Holiday Rambler Neptune 36 PBD 37' - ISB 300 Cummins w/Allison MH2000 5 speed
2005 Malibu Maxx w/Blue Ox Aventa II SMI Stay-n-Play Duo
FMCA - HRRVC - Chapters - 56,57,& 419 - Good Sam Life Member - C2C - Coach Net - full timers
Mike & Sharon
Our Motorhome ran on the warm side after I bought it on E-bay. I talked to cummins and then Freightliner and it was reccomended that I made the vent tube longer and pressure wash the Radiator..After spending a few hours soaking the radiator with Awesom (4 bottles in a hudson sprayer) I then pressure washed the radiator and fan..it looked like mudd as I washed out the radiator and cooler along with all kinds of sticks, leaves, and and what looked like sand...Now it runs at just a bit over 1/3 of the guage and then creeps to just past 1/2 way on hills with the AC on and towing a small car...
Geneva & Warren
04 34m expedition
300 ISB cummins/6speed
Oak hills CA
markz73 wrote: Where is the normal position for the temp needle? Mine runs on the warm side of the mid-range once underway at hwy speed. Not near the red zone, but just wondering what normal is.
I didn't see any reference to the age of your rig, but just assuming the temp gauge is correct, your symptoms are common of a dirty radiator or a partial blockage somewhere in the cooling system. A quick test would be to turn on the cab heater and see if the gauge responds. If so, it's probably not the gauge.
Michael, Kay, Hans (our Mini-Schnauzer co-pilot) and Prissy (Hans' Malti-Poo co-pilot)
'05 Coachmen SportsCoach SE 372DS a.k.a. "Mana's Cabana"
markz73,
You make no reference to your rig and/or the complete instrumentation you have. If you have only the dial gauge on the dash and nothing else, I can understand your concern. I have both the "dial" and a digital readout. My dial reads higher than I would like to see it, normally about the 3/4 point. However, the digital readout on the Light Bar Control Unit consistently reads 194 to 196 degrees under normal driving conditions. I feel that is the more accurate reading since that is what would be pulled up in any diagnostic tests. A diesel engine is most efficient at approximately 195 degrees. Keep your radiator and charge air cooler clean and make sure your slobber tube has been extended to route the oil fumes beyond the suction of the engine fan. Bottom line, I wouldn't be too concerned.
2007 Winnebago Journey 34H
Toad, '08 Ford Taurus X
Blue OX, Aventa
US Gear UBS
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