I'm new to this forum and to owning a diesel. I have 2012 Ram 3500 with about 145,000 miles on it. I'm having an issue with it heating up. It's operating temp is at 206 to 210. When towing or hauling it runs about 225 on flat and up from there going uphill. It hit 245 once. I drove to work this morning (about 7 miles), took the radiator cap off. The coolant was only luke warm but the guage read 205. Where should i direct my attention first, thermostat, water pump, or fan clutch? Any help would be appreciated.
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Your 2012 has a 200° thermostat.
There isn’t a lot of info from Cummins since Ram is the only user I can find for a 200° thermostat in a ISB. When I extrapolate from the specs on a 180° and 190° thermostat this is what I come up with.
Cracks open at 200°±3°
Fully open at 215-217°
Max allowable ~235°
I would expect a 200° thermostat to stabilize while towing grades at around 223°-228° depending on ambient temp and load.
Based on the above info I wouldn’t expect the radiator to be hot or pressurized after a short drive.
225° on the flats and 245° on the hills I would make sure the fan is working by scanning for codes since fan codes won’t always illuminate the CEL, but I suspect the radiator probably isn’t as efficient as it was in 2012 and needs changed out. The thermostat could also be the culprit and would be easy to change, but be sure to use a genuine Cummins thermostat.
I wouldn’t swap in a 190° thermostat without custom tuning since the fan is programmed around a 200° thermostat and those settings would not work on a 190° thermostat.
There isn’t a lot of info from Cummins since Ram is the only user I can find for a 200° thermostat in a ISB. When I extrapolate from the specs on a 180° and 190° thermostat this is what I come up with.
Cracks open at 200°±3°
Fully open at 215-217°
Max allowable ~235°
I would expect a 200° thermostat to stabilize while towing grades at around 223°-228° depending on ambient temp and load.
Based on the above info I wouldn’t expect the radiator to be hot or pressurized after a short drive.
225° on the flats and 245° on the hills I would make sure the fan is working by scanning for codes since fan codes won’t always illuminate the CEL, but I suspect the radiator probably isn’t as efficient as it was in 2012 and needs changed out. The thermostat could also be the culprit and would be easy to change, but be sure to use a genuine Cummins thermostat.
I wouldn’t swap in a 190° thermostat without custom tuning since the fan is programmed around a 200° thermostat and those settings would not work on a 190° thermostat.
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Not necessarily. The scenario the OP listed with a cool or “luke warm” radiator is normal. After a short 7 mile drive the engine is barely at operating temp which means the radiator shouldn’t have any temp or pressure with such a short drive. The fact that it was luke warm means it was doing its job and opening when it should.
The normal empty cruise temps of 206°-210° indicate the thermostat may be slow to open, but the temps the OP is seeing while towing could either be a bad radiator or a thermostat that isn’t fully opening… assuming the fan is working properly.
Will do. Thanks