High Temp Towing Uphill

[Oroman]

Help anyone. I have 2019 1500 classic with 5.7 hemi. I'm towing 7000 lb loaded trailer at 1200 lb total payload (with WD hitch)...I'm towing under my maximums. Yesterday climbed a 6 mile, 6% grade at 45 mph in tow/hail mode. My coolant temp hit 245 - 247 at the top. Yikes. I'm thinking no way is this normal. Gauge was halfway between 3/4 and redline..high temp coolant warning light DID NOT come on. Temp dropped quickly once I started going downhill. I'm waiting to hear from my service manager as to if this is normal...I don't believe it is. Ambient temp was 91 degrees. Again, I'm within towing specs. What's going on here? Can anyone opinion on this?

 

[upwindstorm]

Help anyone. I have 2019 1500 classic with 5.7 hemi. I'm towing 7000 lb loaded trailer at 1200 lb total payload (with WD hitch)...I'm towing under my maximums. Yesterday climbed a 6 mile, 6% grade at 45 mph in tow/hail mode. My coolant temp hit 245 - 247 at the top. Yikes. I'm thinking no way is this normal. Gauge was halfway between 3/4 and redline..high temp coolant warning light DID NOT come on. Temp dropped quickly once I started going downhill. I'm waiting to hear from my service manager as to if this is normal...I don't believe it is. Ambient temp was 91 degrees. Again, I'm within towing specs. What's going on here? Can anyone opinion on this?

These new engines these days run a bit hotter than they use too. although that does seem a tad toasty I wouldn't be surprised if that's normal. did you see what your transmission temp was? that's the one I watch like a hawk when I'm towing heavy. Let us know what your service manager tells you.

 

[Oroman]

These new engines these days run a bit hotter than they use too. although that does seem a tad toasty I wouldn't be surprised if that's normal. did you see what your transmission temp was? that's the one I watch like a hawk when I'm towing heavy. Let us know what your service manager tells you.

Thanks upwindstorm....No I didn't see the trans temp I was so fixated on the rising coolant temp ...my eyes were on the coolant temp only. I have to climb the other side of said grade on the return trip home. I'm waiting for return call from service manager..he is having to call ram hq engineering to get any answers regarding whether 245 coolant is considered normal under those circumstances. On the way home however, my plan is to lock into either 2nd or 3rd gear and climb the grade at say 30 mph and say about 3500 rpm. Climb would take about 12 - 15 minutes. Do you think this would help?

 

[upwindstorm]

Thanks upwindstorm....No I didn't see the trans temp I was so fixated on the rising coolant temp ...my eyes were on the coolant temp only. I have to climb the other side of said grade on the return trip home. I'm waiting for return call from service manager..he is having to call ram hq engineering to get any answers regarding whether 245 coolant is considered normal under those circumstances. On the way home however, my plan is to lock into either 2nd or 3rd gear and climb the grade at say 30 mph and say about 3500 rpm. Climb would take about 12 - 15 minutes. Do you think this would help?

I'm not sure if a slower pace with higher rpms would result in lower temperatures. surely its less work for the motor but you would have less airflow from the truck moving forward. First things first make sure your coolant level is proper, the radiator is clean, fans function and air filter is clean to be productive while waiting for the service managers response. its miserable but if it does start to get hot you can always turn the cab heat to max and roll the windows down to help get rid of some excess heat.

 

[LaxDfns15]

The higher rpm's will lower your trans temp, but coolant is from the load on the engine. Trying not to push the engine faster will reduce the load some, but like upwind said I'd be more focused on trans temps. You're basically doing a mini Ike Gauntlet.

 

[Buz]

You pulled 7,000lbs up a 6% grade (which is hard work) and the temp light didn’t come on. Bet it’s normal.

 

[Oroman]

You pulled 7,000lbs up a 6% grade (which is hard work) and the temp light didn’t come on. Bet it’s normal.

Actually I was towing 6800 lbs loaded. Max towing is 8300. GCWR is 13800, which I am under that and payload by 300 lbs. Have I been duped by the towing specs? I knew I was towing under specs before I bought the 1500. It makes me wonder under what conditions Max towing numbers are established!

 

[devildodge]

Yes. The towimg numbers...it is your empty truck and everything you can put in the truck and trailer.

See this. 13900 minus 8300 is 5600...that is the base weight of your truck...so no driver...no hitch...can not be done.

Your payload must be 1500lbs...an above avg payload...which ia good.

You are near the towing capacity which is why your truck hit 245. A camper makes that worse...because of the drag.

Towing capacity is figured with an equipment trailer.

I will say this again. Campers can not use the towing numbers

You say your trailer weighs 6800 lbs. 12% is 820lbs.
Have you gone to a CAT scale to be sure of this number?

So your truck weighs 5600 and your trailer with tongue weight is a guesstimate of 7620 which is a combined of 13220

So you have 680lbs left. 120lbs for hitch...560lbs.

So all your passengers and truck have to be under 560lbs. In my case I weigh 300lbs myself...

Your truck was working.

Hope this helps. Hope you have a safe trip home

 

[devildodge]

I just noticed you have the classic. So you are down 300lbs of capacity over a 5th Gen.

So change 7100 to 6900 and 13900 to 13800.

So 13800 minus 8300 is 5500. Payload would be 1400 lb

5500 plus 7620 is 13120 which leaves you with the same 680lbs.

Sorry for the oversight...but in the end they worked out similar.

 

[RunsWithBeer]

Help anyone. I have 2019 1500 classic with 5.7 hemi. I'm towing 7000 lb loaded trailer at 1200 lb total payload (with WD hitch)...I'm towing under my maximums. Yesterday climbed a 6 mile, 6% grade at 45 mph in tow/hail mode. My coolant temp hit 245 - 247 at the top. Yikes. I'm thinking no way is this normal. Gauge was halfway between 3/4 and redline..high temp coolant warning light DID NOT come on. Temp dropped quickly once I started going downhill. I'm waiting to hear from my service manager as to if this is normal...I don't believe it is. Ambient temp was 91 degrees. Again, I'm within towing specs. What's going on here? Can anyone opinion on this?

Gravity and trigonometry.

You're effectively towing more weight up a hill.

The total weight of truck + your load. With the narrow margins on our half ton trucks, you're probably exceeding the GVWR.

I'll leave the calculation to nimbler minds.

 

[Gusman4]

I have a 2019 rebel 5.7 Eco. Towing my 5000lb travel trailer up Eisenhower in CO I saw coolant temps around there briefly when I pulled over to grab a water out of the back of truck. When I got back in I saw coolant temp was really high 245 or so. As soon as I started moving again it went back down and stayed in the 220’s 230’s when it was working hard on the passes. I was keeping 55-60mph up both Eisenhower and vail passes so it was working hard. But no lights or any warning when it rose to the mid to high 240’s.

 

[Oroman]

I did weigh my truck and trailer..without going through all the numbers, I am 360 lbs BELOW my GVWR of 6900 and Max Payload of 1587. I am also 1,090 lbs BELOW my GVWR of 13800. I knew these would be the numbers before I bought this truck ... Never knowing how hot the HEMI runs. Now I'm stuck. I simply want to know is this normal? Is it possible that my temp sensor is reading too high? Since the temp dropped pretty quickly once I crested the severe grade, is it likely that occasional and brief coolant temps of 245 won't damage engine?

 

[SD Rebel]

Help anyone. I have 2019 1500 classic with 5.7 hemi. I'm towing 7000 lb loaded trailer at 1200 lb total payload (with WD hitch)...I'm towing under my maximums. Yesterday climbed a 6 mile, 6% grade at 45 mph in tow/hail mode. My coolant temp hit 245 - 247 at the top. Yikes. I'm thinking no way is this normal. Gauge was halfway between 3/4 and redline..high temp coolant warning light DID NOT come on. Temp dropped quickly once I started going downhill. I'm waiting to hear from my service manager as to if this is normal...I don't believe it is. Ambient temp was 91 degrees. Again, I'm within towing specs. What's going on here? Can anyone opinion on this?

If the high-temp light didn't come on, you should be within range.

However, someone recently had an issue that only showed up while towing, it turned out haft his radiator was covered in mud from off-roading which hurt his cooling. It wasn't noticeably under normal driving, only under stress. He bought the truck used, so he had no idea the radiator fins were covered up until after he took it to the dealership. Good idea to double check your radiator just to make sure it's free of any debris.

Also, here is a good video that shows temps for extreme towing done with a current gen RAM, it should still be similar to the temps you are getting. Over 11,000 feet elevation, It is a 7% grade w/ over 10,000 lbs towing for about 8 miles. More extreme to what you were doing, but still a good comparison.

Their coolant temp at the end of 8 miles was 240F, with Oil Temp at 287F. Based on this, your coolant temp is close to theirs, but you are towing under less extreme conditions. Did you get your oil temp as well during this time? If it's similar to theirs, then you should be normal. If it's significantly lower, then you maybe got a radiator issue.

See at 9m25s on the video for final temps at the top

 

[devildodge]

I did weigh my truck and trailer..without going through all the numbers, I am 360 lbs BELOW my GVWR of 6900 and Max Payload of 1587. I am also 1,090 lbs BELOW my GVWR of 13800. I knew these would be the numbers before I bought this truck ... Never knowing how hot the HEMI runs. Now I'm stuck. I simply want to know is this normal? Is it possible that my temp sensor is reading too high? Since the temp dropped pretty quickly once I crested the severe grade, is it likely that occasional and brief coolant temps of 245 won't damage engine?

Then you are good. I see people all the time guess at their numbers. And you can see that the numbers I got from the numbers you gave in the post are nowhere near what you just said.

It usually goes the other way.
Sorry for asking...but I like to know what we are working with

If the numbers listed here are correct. Then 245 deg coolant is a non issue. If it would have stayed high after the climb...then there would have been a problem.

You are good to pull. Remeber...the Hemi makes its power above 4500 Rpm...so that is where it needs to be.

 

[Buz]

Until you get an 'overtemp' light/warning the RAM is working within it's designed parameters.
For all intents and purposes you were closing in on a key maximum weight and dragging it up a pretty damn steep hill.

 

[Oroman]

Buz ..that does sound reassuring that I'm OK if temp engine light didn't come on. But, my coolant gauge was at about 7/8 ...
So the big question is, if I had been climbing an even longer grade, I assume the temp would have gone higher, say 250? Or would the temp stabilize? Just when would the light go on? At what temp? In the aforementioned video, which I had seen before, the Rebel had 3.92 gears. Interesting in that video, at 10K lbs coolant temp was lower than mine. So I wonder if I upgraded my gears to 3.92, would I run cooler with an increased towing rating up to 10K towing the same 6800 lb trailer? Does anyone know at what temp and gauge position coolant warning light comes on? Also should I take cruise off and just lock into a lower gear to bring the rpms up to 4500 while climbing the grade as devildodge has mentioned?

 

[Buz]

Buz ..that does sound reassuring that I'm OK if temp engine light didn't come on. But, my coolant gauge was at about 7/8 ...
So the big question is, if I had been climbing an even longer grade, I assume the temp would have gone higher, say 250? Or would the temp stabilize? Just when would the light go on? At what temp? In the aforementioned video, which I had seen before, the Rebel had 3.92 gears. Interesting in that video, at 10K lbs coolant temp was lower than mine. So I wonder if I upgraded my gears to 3.92, would I run cooler with an increased towing rating up to 10K towing the same 6800 lb trailer? Does anyone know at what temp and gauge position coolant warning light comes on? Also should I take cruise off and just lock into a lower gear to bring the rpms up to 4500 while climbing the grade as devildodge has mentioned?

I honestly don't know the answer to most of your questions, but would definitely try locking out a gear to get your engine more into the meat of the rpm powerband. I won't dare comment on the 3.21 rear end though. Not wearing my bullet proof vest today.

 

[J-Cooz]

Buz ..that does sound reassuring that I'm OK if temp engine light didn't come on. But, my coolant gauge was at about 7/8 ...
So the big question is, if I had been climbing an even longer grade, I assume the temp would have gone higher, say 250? Or would the temp stabilize? Just when would the light go on? At what temp? In the aforementioned video, which I had seen before, the Rebel had 3.92 gears. Interesting in that video, at 10K lbs coolant temp was lower than mine. So I wonder if I upgraded my gears to 3.92, would I run cooler with an increased towing rating up to 10K towing the same 6800 lb trailer? Does anyone know at what temp and gauge position coolant warning light comes on? Also should I take cruise off and just lock into a lower gear to bring the rpms up to 4500 while climbing the grade as devildodge has mentioned?

I don't think you can compare your classic to the 5th gen. The cooling systems are different. I wouldn't worry about the gauge position. If you didn't get an overtemp warning you are fine.

 

[Oroman]

J-Cooz: Thanks for comforting feedback. You did see I noted that coolant gauge was at 7/8 toward max? What is it about the 5.7 classic's cooling system that apparently allows for coolant temps over 240 - 246 without engine damage? Does the coolant warning light ever come on? If so when? Gauge at 100%?

 

[2wd]

Remember from 2011-2018, the 5.7 was the standard engine offering in the Ram 2500/3500. Those trucks had the 68rFE trans, which had worse towing gearing/final drive ratios than the 8 speed 3.21. Those trucks were rated to tow well over 10,000 lbs, not to mention the truck itself was heavier.

The cooling systems could have been better in those 4th gen HD's, but I'd consider searching the HD forums for HD trucks w/5.7 having overheating issues when towing. [Or what temps were they seeing when towing].