Engine running very hot when towing over mountain passes

[denali1322]

Curious what others experience when towing over mountain passes. Even though my truck is a 2018 (sport edition), I haven't towed extensively with my larger trailer and 2 ATVs (about 5500 lbs) until this summer and am noticing things getting really hot - coolant (240) and engine oil (266). It's not even super hot outside (maybe 80 degrees), but it's not uncommon in Colorado to have multiple 4,000 foot elevation gains during one day's driving. I did not have the AC on, but I did not turn the heat on. I've taken it to the dealer and he's saying everything checks out (thermostat looks fine, fan working well, and radiator has good flow in it) and I shouldn't be that concerned with temps in that range as these diesels run hot. I'm not a gearhead, but seeing my coolant gauge nearly in the red is concerning.

I was thinking about getting a travel trailer, but honestly it feels like it can barely handle 5500 lbs (temp, the engine has no trouble towing).

 

[basedaf]

So on my truck, 2016 Ecodiesel Longhorn Crew, 6'4" bed, 3.55 gears, the rated payload is 1260 and rated tow capacity is 7540. Also in CO. I can get my coolant temps well into the 230s while empty with spirited driving or going 80-90 on the empty back roads when I'm running late. Short answer to your question is it's normal and you'll need to slow down uphill (like to about 40-50mph) while going I-70, 285, etc and towing that kind of weight. There's also a good chance if you have all your camping gear, coolers, extra fuel, family members etc, you're probably well over the GCWR anyway.

Long winded answer: I haven't looked into beefing up the cooling system but I kinda doubt there's any factory-made upgrades, and if it's too much cooling and keeps normal driving temps under 200, you'll lose efficiency for the diesel motor being too cold. I have this truck as my going around town truck to get 23+mpg. My Ram 5500 work truck handles moving my equipment and pulling the 5th wheel. It also gets 8mpg most of the time, empty or loaded. The 5500 is also de-rated in the computer system to handle mountain passes with 40k lbs behind it, so even if I mash the accelerator while climbing the mountain, the truck won't rev any higher than it wants to and it stays at a nice 220 degrees fully loaded...... At 40 mph and won't go faster. If you're pulling 5000+lbs on a regular basis or if you're looking at a travel trailer larger than 16' or so, I'd probably start looking into a bigger truck.

Here's the official Ram tow and haul capacities chart: https://www.ramtrucks.com/assets/towing_guide/pdf/2016_ram_1500_towing_charts.pdf

 

[denali1322]

Thanks for sharing your experiences. I have only been driving 45-50 mph (I live in Salida and drive over Monarch regularly) and had nothing in the truck the last time I took the ATV's up and saw coolant at 240 and oil at 266. Seems really hot, but sounds like you live in the 230's and your vehicle has never flashed warning lights or gone into limp mode. I saw somewhere else (maybe in this forum) that the vehicle will derate at oil temp of 270 (not sure if that is true, but I was super close to that). I was looking at a travel trailer well below the tow capacity of 7,990, but even smaller trailers seem to have weights at least 6500 and many closer to 7,000. Maybe I'll just keep testing it out with the 5500 lb trailer load and see how it does at cooler temps. The radiator had a leak a year and half ago and I had a small shop swap out the radiator (probably not an OEM replacement). I never noticed such heat until that replacement so wondering if even though it's "working" it's just not as good a radiator. I wish I had the skills to replace a radiator as the part is relatively inexpensive, but the labor to have that done (at least in Salida) is easily $1,000, if not more.

Curious how hot others regularly sees their ecodiesel? Also curious if anyone has found a really high performing radiator. Not looking to get coolant super cold, but wouldn't mind to see it at more like 225, not 240+. I definitely don't want it to ever go into limp mode at 12,000 feet on a two lane road with no shoulders.

 

[autoX]

Engine Temp = Horsepower (T*rpm) + Ambient - Cooling capacity.

So at that power output, adding in the ambient, you get a certain temp on the gauge. Higher the ambient, higher the gauge.

I think it's ok, steady state no problem. Lot of ponies in a small space too. So I thought why not use some sort of misting system using evaporation cooling. I googled and found

Radiator Mister

Radiator Mister - SEMA Show Award Winner This is an overheating solution that sprays a mist of water onto the front of the radiator and can reduce a vehicle’s temperature 20 degrees in a matter…

ve-labs.net

It's a problem if it goes meteoric. You know like back in the day when steam was blowing out everywhere, and the gas station guy had a rag and was scalding his arms,....