Overheating While Towing in Mountains

[5thGenLoco]

Something to check is actual temps vs what the truck is telling you. There are infrared thermometers or internal thermometers that you can use to verify.

 

[H3DX]

OK, I have one. Where is best place to point it?

 

[Richard320]

OK, I have one. Where is best place to point it?

I'd shoot it at the upper radiator hose. Or one of the heater hoses adjacent.

 

[silver billet]

I would also try to measure it at the block somewhere if possible, it seems his coolant is high-ish but comes down in 20 seconds (according to his first post), so the engine oil appears to be the biggest issue from what I can see.

 

[blakei]

Here are some temps from a recent tow on I70 and I15 westbound through Colorado, Utah, and Nevada for reference. Our Jayco 28BHS TT was about 8200 lbs loaded on this trip.

Ambient / Coolant / Transmission / Oil (all temps in F)
90 / 221 / 197 / 264 (just crested slight grade)
85 / 226 / 201 / 264 (4%? grade)
108 / 215 / 188 / 239 (flat)
112 / 215 / 195 / 248 (4%? grade)
108 / 212 / 188 / 248 (flat)
98 / 224 / 203 / 271 (4%? grade)
73 / 208 / 183 / 240 (flat; coastal CA for this low ambient!)
108 / 237 / 208 / 275 (diff trip on CA 168, ~7% grade)

At this point, I basically don't worry about temps unless it's very hot (100F+) and then I watch the oil temp and slow down on grades if it is headed over 270F -- like that last one, where I just cruised up the last couple of miles at 45MPH instead of trying to maintain 55-60MPH.

If people are REALLY interested it's possible to use a data logger in the OBDII port to record all the data points during a trip.

 

[nc_beagle]

What would be a good "yellow light" number for coolant, transmission, and oil temps? A level that tells me to start taking it easier before I hit "red."

I'm in an Ecodiesel.

 

[GKIII]

What would be a good "yellow light" number for coolant, transmission, and oil temps? A level that tells me to start taking it easier before I hit "red."

I'm in an Ecodiesel.

Depends on what the design limits of the truck are, every model is different. The truck will start yelling at you long before you can cause damage (temperature-wise at least).

 

[nc_beagle]

Depends on what the design limits of the truck are, every model is different. The truck will start yelling at you long before you can cause damage (temperature-wise at least).

OK. I planned to leave the 7" display on the screen that shows the different operating temps and wanted to know when I was approaching high temps for each item.

 

[GKIII]

OK. I planned to leave the 7" display on the screen that shows the different operating temps and wanted to know when I was approaching high temps for each item.

I do not know the trans and oil temp limits in the truck, but the coolant temp warning will come on as you're nearing 250. I'd back off if it hit 240 personally and you're not likely to hit that unless you're towing near the limits of the truck on some really steep grades on a very hot day. The OP here clearly has something wrong with his vehicle.

 

[dannymcd]

I've got a 5th gen 2019 with the highway diff not the max tow, I was pulling a 7600# trailer thru WV, on a 2-3mi stretch at 6-8% I got to 220-180-275 as well. The coolant and trans went up maybe 10-20° compared to driving without any load but that oil temp, normally around 227, and 240 when towing hit that 275 mark as well. I use Amsoil HD oil so I'm not too concerned about the oil burning being at that temperature for 4mins before going back down. I was looking for a simple cooler addition as a fix but like many things I'm finding there's not alot of wrencher's on this forum so I think I'm going to figure it out on my own and do a write up.

 

[Eighty]

I'm finding there's not alot of wrencher's on this forum so I think I'm going to figure it out on my own and do a write up.

One of the users called me a tool earlier today - does that count?

 

[dannymcd]

One of the users called me a tool earlier today - does that count?

It depends on what tool you are, if you're a 10mm socket you're always lost, haha. Personally I see myself as I'm an angle grinder, the cheapest power tool in the box, always the last one to be used and i'll do some real damage to your paint if you cut me off on the highway.

 

[silver billet]

It depends on what tool you are, if you're a 10mm socket you're always lost, haha. Personally I see myself as I'm an angle grinder, the cheapest power tool in the box, always the last one to be used and i'll do some real damage to your paint if you cut me off on the highway.

I'm more of a belt sander type of guy; not the sharpest tool in the shed, and I'll wear you down with my abrasive stupidity!

 

[Albab930]

I recently bought a RAM1500 Hemi 5.7 3.92 4x4 to tow our travel trailer from Denver to west slope and Utah. We hoped to make ~6 round trips per year (24 ascents over Vail Pass + Ike Tunnel). Made 2 runs so far and it's a FAIL. Truck now has 1300 miles on it and I got the Engine Temperature High warning on both Vail and Ike. The load is a Little Guy (3150lbs dry) with ~600lbs of stuff in it, and a payload (people and toys) of about 600 pounds. Tongue weight is ~350. Not a heavy load, I thought. Tried to maintain a reasonable speed going uphill of 55mpg (speed limit is 65, and many trailer rigs were doing that). Pretty near the top of the passes, gauges read (249, 199, 275) for coolant, tranny, oil. I recovered from the coolant warning by turning ac off, heater up to the max, and slowing to 40. Coolant went down to 228 in 20 seconds , but oil stayed high (270, no oil temp warning) until we started the descent.

I assume this is not normal, and perhaps dangerous to engine? After the first fail, it went in for warranty service - they found nothing wrong.

Do I have a lemon, or is the design such that you can't run at 300hp for 10 minutes? The latter would be pathetic.

Too bad because I really like the truck. Gets 12mpg towing these big hills, is comfortable, can keep up good speed (though only for a short time before overheat).

Suggestions? Thanks.

Hey HD3X, did your overheating issue get resolved? I am experiencing EXACTLY the same issues you described. Pulling a travel trailer of less than 4000 lbs and overheating going up Colorado mountain passes. I am out of warranty and had a reputable shop replace the fan clutch, water pump and thermostat. Hoped that would fix the issue. Took off last weekend and overheated pulling up La Veta pass (US 160). Needless to say I’m very unhappy. Got overheat warning at about 250 water temp, 255 oil temp and tranny at 198.
Would like to hear if and how your issue was solved.
Thanks!

 

[Paul B]

Are you guys letting the granny do it's thing??
If so, try manually downshifting to lower gears, yes it will roar, but you need more RPMs.
My diesel did the same on Vail pass, I down shifted to 2nd and all cooled down to normal.
Paul B