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Overheating While Towing in Mountains

What is the frontal area of your trailer? Basically I'm asking if it's a brick in the wind or has some streamlining. I know somewhere in the depths of the towing guides they take into account frontal area of the towed vehicle can't be greater than X sqft @ XXXX weight. Maybe that's your problem and it's amplified by speed and incline?

Max frontal area is 60 sq-ft.
 
Others might disagree, but if I were you I'd change out that oil to a high quality full synthetic tomorrow (or asap), before your next trip. Even if it's not redline which is my goto at the moment, something good. For a start your current oil is probably on the way out anyway (anything above 250 is bad news for standard oil), and this would be a great test to see if a different/better oil helps mitigate this kind of problem, it's great real world testing with no marketing spin or agenda being pushed by somebody. I'd prefer a 5w-30 but would understand if you don't want to go that far.

In fact, if you wanted to run this test, i'd be happy to paypal you $50 to put towards it? I'd just need your forum username printed on a paper next to the dealer receipt and include a screenshot of the temps of your next trip on that oil as some sort of proof I guess. Honestly, this type of feedback would be invaluable to me and I'm sure to many other forum members.
Sure, no need for cash. I ordered RL 5-20 and will put it in before my next mountain pass run (aug 12). I video the guages the whole way up with a gopro, so plenty of data ;-).
 
Max frontal area is 60 sq-ft.
Interesting thought, but I can't imagine that's much of a load at 50mph in thin air at 10,000 feet.
The frontal area is about 49 sq-ft, and the front is quite curved which must give some sort of streamlining.TheRig.jpg
 
Interesting thought, but I can't imagine that's much of a load at 50mph in thin air at 10,000 feet.
The frontal area is about 49 sq-ft, and the front is quite curved which must give some sort of streamlining.View attachment 100768
...I'm not gonna lie. I laughed out loud after I asked about your frontal area and you respond with that picture.

Definitely a problem with the truck..

Mine pulls this without heating up.
 

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Interesting thought, but I can't imagine that's much of a load at 50mph in thin air at 10,000 feet.
The frontal area is about 49 sq-ft, and the front is quite curved which must give some sort of streamlining.View attachment 100768

I’d bet it’s less than 49 sq-ft. The listed height is ground to top of A/C. Need to subtract ground to box & a/c height
 
holy crap 275...., you might have burnt your engine oil, but definitely start with going full synthetic.
3500lb trailer and 82 outside temp isn't that crazy... might be something else going on...
I know gas motors aren't the best for towing up hills but it still shouldn't be this bad.
You have an issue. Don' do anything that they can use to void your warranty at this point. Let them do any work. You are in CYA mode.
 
Other possibility is that your engine was pinging like a pixie on 87 octane gas. Perhaps try running 89 for the higher elevations and towing. This can cause some overheat issues if happening often.
 
Other possibility is that your engine was pinging like a pixie on 87 octane gas. Perhaps try running 89 for the higher elevations and towing. This can cause some overheat issues if happening often.
I was running 91 (can't get routinely 89 in colorado).
 
You have an issue. Don' do anything that they can use to void your warranty at this point. Let them do any work. You are in CYA mode.
Yes, I am documenting everything, and counting the incidents and service calls, just in case it's a lemon. I don't think putting in full synthetic 5-20 would void warranty?
 
Did you try locking out higher gears? High engine loads produce high heat.
RPM seemed to adjust into max torque range. It was not pulling uphill in overdrive. I did use tow/haul mode on some ascents, made no difference.
 
Yes, I am documenting everything, and counting the incidents and service calls, just in case it's a lemon. I don't think putting in full synthetic 5-20 would void warranty?
No, it is 100% acceptable (and IMO highly recommended for use cases like yours) to use a full synthetic. Redline does recommend their oils for MS6395 spec compatibility but they don't actually pay for the certification. The 100% CYA move is to use something like Pennzoil Platinum/Ultra Platinum or Rotella Gas Truck Synthetic (or any other full synthetic that carries the MS6395 certification).

Like I've said before I'm not all that concerned with the ~270F oil temps for your specific issue. Other guys have seen oil temps that high when towing. Your truck shouldn't be hitting 248+ coolant temp though.
 
Found a 5th Gen Hemi towing 7k going up the Ike @ 60 mph.

Coolant: 221 F
Trans: 206 F
Oil: 275 F

FCF3872F-DBCD-452D-8ADA-B0F78FF306C1.png
 
Found a 5th Gen Hemi towing 7k going up the Ike @ 60 mph.

Coolant: 221 F
Trans: 206 F
Oil: 275 F

View attachment 100882
This video finally made me decide I'd go with a 3.21 rear end. The truck had everything I wanted except a 3.92. I have a 6700 fully loaded travel trailer, the truck has an 8100 tow rating and 1300 and change payload. My payload will be up there in the ballpark, but I have around 1400 leftover on the total tow rating and yes, I understand ALL the ramifications...get it...
 
This video finally made me decide I'd go with a 3.21 rear end. The truck had everything I wanted except a 3.92. I have a 6700 fully loaded travel trailer, the truck has an 8100 tow rating and 1300 and change payload. My payload will be up there in the ballpark, but I have around 1400 leftover on the total tow rating and yes, I understand ALL the ramifications...get it...

You’ll be fine. I towed a TT of same weight with 5.7L/8HP70 and 3.09 axle ratio. Power wasn’t an issue
 
Do you happen to have the video link for that too?
Wow, pulling almost 2x the trailer weight up the same guantlet. Same oil T as me (275), but much better coolant (221 vs 250), and 60mph vs 55'ish. But, outside air is only ~57 (vs. ~84), so I presume they didn't have AC on.

My truck goes in for service Weds. What can be wrong with a brand new cooling system? TC checked OK after first fail, air bled (after dealer checked TC), fans OK too. No leaks. What's left? Plugged hoses maybe (new though), bad waterpump? Anything else?

Thanks everyone for all the info.
 
Wow, pulling almost 2x the trailer weight up the same guantlet. Same oil T as me (275), but much better coolant (221 vs 250), and 60mph vs 55'ish. But, outside air is only ~57 (vs. ~84), so I presume they didn't have AC on.

My truck goes in for service Weds. What can be wrong with a brand new cooling system? TC checked OK after first fail, air bled (after dealer checked TC), fans OK too. No leaks. What's left? Plugged hoses maybe (new though), bad waterpump? Anything else?

Thanks everyone for all the info.

The official SAE towing test is a ~12 mile, 3000 ft elevation change route...with some grades at 7%. The test is performed when ambient temperatures are over 100 degrees with max AC (higher blower setting, lowest temp, outside air) running in Arizona. Trucks must be able to maintain at least 40mph with NO engine warning lights. The 40mph requirement makes it a little less strenuous than going 60+ up Ike but not THAT much considering ambient temperatures are much higher.

Your truck should be able make this pass without overheating, especially considering you are not at all close to your towing capacity limit.

If the system is bled and fan is running fine then I'd be looking at the water pump.
 
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I hauled about 6500 lbs in my 2021 Hemi Etorque in 110 degree weather recently and had no problems whatsoever
 

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