‘19 surging when towing, what could it be?

[Calidad]

Ok not done with my 776 mile haul yet. But 8000lbs 13ft high 9.9 wide boat across a couple of west coast passes. Today 101-103 outside temps.

55-60 mph top gear 8th, typical gear 7th, and climbing gears 6,5,4 and yes 3. We ran AC on the flats zero issues, once outside temps hit high 90’s the coolant temp would spike which triggers actual temp display next to the dummy gauge 228 was the bottom any lower it goes away very quick to drop when you cut the ac or if in a heavy long climb run the back or both heaters. Like 30 seconds **** back to normal temps.

Transmission normal range is 200-214.

All my hard long climbs I found 2100-2200 rpm was the magic zone lots of power and transmission temps didn’t spike hard. Worst climb 5 mile 6% in 103 temps we crested the top at 235 no warnings or limp modes 250 is limp mode. In extreme cases 103 temps and brutal long climbs dragging a huge ass boat the rear and front heaters at full blast with windows down is extremely quick at cooling temps down on the dash.

Basically worst case situation it was very easy to manage heat spikes and keep the Expedition in a safe but occasionally warm zone being pushed hard.

Only times I was pushing 3500+ rpm were engine braking cases. Even steep freeway ramps 3500 was all that was needed for a very short get up to speed effort.

I’m only doing 55-60mph when your 54ft long and over 9ft wide thats plenty fast. 9.4 mpg has been my average for the last 500 miles.

Transmission temps spiking to 219-225 are easily managed by dropping rpms below 2500, and if temp keeps creeping up run the heaters.

Little trick no rear passengers? Crank the rear heat open the windows, turn off front ac but skip the front heat. Still sheds lots of heat and you definitely see temps drop pretty quickly.
This is an extreme case. This isn’t a trip I’d make on a regular basis. F250 would be my choice for a regular case.

This adventure is bringing a boat home from a place it will probably never return to. And future tows will be nothing remotely as extreme.

 

[JasonH]

This adventure is bringing a boat home from a place it will probably never return to. And future tows will be nothing remotely as extreme.

Thanks for explaining why you're hauling a boat so far, because inquiring minds want to know. My office manager hauled hauled his last boat from Texas to Irvine. Are long distance purchases a normal thing for boat buyers?

 

[Calidad]

Bought a boat in Seattle brought it home to CA Friday. Had to get a diesel 2500 GMC to do the final pass into the Sierras. Didn’t cook the EXP just knew we weren’t going to do the rest of the climb from 5000ft to 7200. 20 miles from home base. No big deal. Engine temps were normal whole trip. Transmission temps were the Clear must watch item. But easy to manage. When your clearly over capacity your only going a few 100ft before you see trans temps rising fast. If its rising pretty quickly over 214 up to 219-220 pull over let it run and cool off. It will continue to rise 2-3 degrees for a few minutes but begin cooling down. 80 degree day with heaters on figure 15min to see a drop to 210 ish on trans temp

 

[Calidad]

I don’t recommend doing this. But in a pinch 8200lbs 740 mile trip with the worst climb 5 mile 4-6% varying grades in 80-90 degree temps. 2000-2200 rpm is the best for heat management and forward progress.

Flat towing in 100-103 temps same 2000-2100 6-7th gear occasionally 8th on down hill ish runs works best.

My truck is intact never cooked but we did stop for a couple of cool downs when we hit 219 trans temp with more climb left ahead of us in hot 90+ outside temps.

Coolant temp if it warms up past center it will pop up actual temp next to the dummy gauge 228 is the trigger point, once it drops below 228 it reverts to the dummy gauge. Super quick to drop coolant temp by slowing down, dropping RPMs to the 2000-2100 range lighter throttle, run heater etc. Like a minute or less to drop temp if you take action right when it spikes its a quick easy effort to drop temp.
In case your wondering I had 2.5inch squat. Truck was empty except two adults and 60lbs of gear. Trailer is electric / Hydraulic 4 disc brakes serious brake power. Lots of hauling experience it wasn’t as good as a F250 but can get the job done if your cautious and know what your doing.
Fully permitted in three states not hassled by any highway patrol entire trip.

Mileage ran between 9.4mpg and 7.4mpg.

Higher RPMs 2500-3000 most definitely generate far more heat. Likely related to turbo heat under harder throttle.

Power? Easily accelerated to highway speeds even with short rampand steep climb, power is definitely NOT an issue its cooling you run out of quickly especially 2500+ rpm.

I can see people easily cooking the 3.5 and 10spd because of its huge torque and power under heavy load without paying attention to temps