2019 Max overheating when towing

A friend with a Raptor and the 10spd mentioned a recent experience similar to this. He was dragging a side by side. No idea how fast he was going.

I wonder if there is some sort of programming logic affecting how the 10spd is holding or slipping gears etc?
I haven’t towed yet and likely won’t drag more than 1500lbs for the next few yrs.

Soliyou said:

A youtube video of a 2017 Econoost owner with the same problem. Turned out to be a defective radiator:

Click to expand...

My first thought was a friends old Explorer that kept having transmission over heats. For yrs the Ford dealer said can’t find s problem. Finally some crust old guy at the dealer literally asked if anyone had checked to see if the cooler wasn’t plugged. Nope never checked. Yep bad weld in the cooling loop blocked the flow. New cooler never had an issue again.


My money is on a faulty transmission cooler. I haven’t looked are these combo radiator coolers or the old school external cooler?

Calidad said:

My first thought was a friends old Explorer that kept having transmission over heats. For yrs the Ford dealer said can’t find s problem. Finally some crust old guy at the dealer literally asked if anyone had checked to see if the cooler wasn’t plugged. Nope never checked. Yep bad weld in the cooling loop blocked the flow. New cooler never had an issue again.


My money is on a faulty transmission cooler. I haven’t looked are these combo radiator coolers or the old school external cooler?

Click to expand...

Except in this case the transmission isn’t actually over heating and throwing an error. It just gets hotter than the OP is used to seeing on different (older) transmissions.

I do see new cars running higher temps. My 19 runs at 197-200 just doing 35mph kid hauling across town. I know 230-240 seems to be typical temps now days even with CVT transmissions. I recall 260 starting to reach into the high side tho for ATF fluids. It would be interesting to know what temps start to cause warnings and what temps cause actual problems etc.

shane_th_ee said:

If you weren't getting error messages... Page 58 shows an average engine oil temp between 212 and 230F and 240 isn't that much higher. Without looking at the detailed test procs, I'm pretty sure that's not a towing/heavy payload test.

https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/documents/812520.pdf

Click to expand...

I've noticed that this system allows for much higher "normal" temps. I see 230F coolant without towing. Ive seen 235F towing. No warnings.

2018 Expy Platinum Max
475whp on 93

Mishimoto trans cooler
Mishimoto radiator

Tow 8,000# TT regularly through the Smokey mountains

240* is way too hot for both trans & ECT coolant temp. The original factory set up slipped like crazy & you could smell the discs burning. I would have had to go like 50-55 mph & you had to run boost & not rpm’s or else ECT would overheat, by running gearing. Now I can run gearing/rpm’s & not worry about overheating, which keeps the engine load down as well. Since I noticed the high load situation is what creates the trans slipping & bucking.

Your 10R80 will start slipping easily by 235* & higher. Could be simple fix like the internal thermostat control valve, which opens to allow trans fluid to circulate through the the trans mounted heat exchanger—it’s not really a cooler.

That has been known to get stuck, basically, it’s the same as having a stuck thermostat.

I know Ford wants to run these transmissions at higher temps than traditional, but I still think this is just asking for problems & shortens the life of the trans—heat still kills transmissions.

Ford runs a heat exchanger, which circulates engine coolant, through the trans mounted heat exchanger.

This means that the trans temp will never be colder than the engine coolant, so if your engine coolant get hot, like say 230 & higher, then your trans cannot be any colder than the engine coolant temp.

I removed the trans mounted heat exchanger & mounted a Mishimoto trans cooler up front of the new mishimoto radiator & run a 180* stat. Factory is 190.

Trans temps run 150s-160s flat land towing & 175-195 towing mountains, max around 215 after towing up steep grades & then immediately stuck in traffic, so no air moving through the cooler stuck in traffic, it will warm up a bit from heavy work up the mountain & then immediately cool off once you get moving again.

ECTs run low 190s up to 210 while towing up hill,
& around 215 doing WOT 1/4 mile pulls

Stinks Ford doesn’t build it right, to begin with, so I would either had to get rid of it, or fix it right. So, decided to fix it, since I’ll have it a few more years.