Overheating - 2018 4x4

Intermittently, my 2018 is spiking a fever.

The image below is the worst that happened, and yes, as I approached this I pulled over, turned it off and opened the hood to cool down.

This image is AFTER the repair shop spent 6 hours under the hood, bled coolant lines, installed a new thermostat. I am about to take it back in for a full week of exploration (water pump, flush system, etc.) but am looking for ideas of what might cause this in around-town driving.

If we look at C as 0 and H as 10, the meter will be at a 5 for a while, allowing me to do short errands, but after 30-45 minutes, or maybe 60-90 (no firm correlation), BAM! Have to shut it off, pop the hood and cool down.

Yes, this is the ONLY time it got THIS hot as I was trying to make it the last 1/2 mile home with 3 kids in the car... we didn't make it and had to cool down for 20 minutes.

Thanks in advance for ideas that I can pass on to the shop (which has a Ford certified mechanic).

This is your transmission gauge and it basically reached a critical point for temps. You talk about new T-stat, etc., what are your ECT's?

There may be a bigger problem at hand unrelated to the cooling system.

did they use genuine ford parts for the thermostat etc ? I watched a car diagnostic video the other day where a brand new aftermarket thermostat freshly installed by a prior shop just plain didn't work.

Agree. Need a new OEM thermostat from the dealer and possibly a new housing.

What is your water temp though? The gauge you are showing is the transmission temp. If the transmission is getting that hot there is a bigger problem going on, especially if your coolant temp isn't that hot. Either the heat exchanger for the transmission isn't working, or the transmission has a major issue. What is your coolant temp when this is happening?

duneslider said:

What is your water temp though? The gauge you are showing is the transmission temp. If the transmission is getting that hot there is a bigger problem going on, especially if your coolant temp isn't that hot. Either the heat exchanger for the transmission isn't working, or the transmission has a major issue. What is your coolant temp when this is happening?

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Oh wow, I just quickly glanced and thought that was coolant temp.Yes - what is the coolant temp? Is there an internal bypass or thermostat for the trans cooler that may have failed?

Coolant temp (ECT) is the thermometer in rippling water symbol.

There is no bypass or tstat for the transmission. Just additional lines that run to a heat exchanger.

There has to be a major problem with the transmission, if your coolant temp isn't also very hot. What ever shop you went to didn't know what was happening, or what they are doing, you really probably need to get this to a dealer and have the transmission looked at.

Did you have the fluids changed or topped off before problems started?
Simple wrong fluid level could do this as well. Seems like dealer did a lot to control engine temp/coolant but if there's TOO MUCH trans fluid, this will happen.

slow3v said:

Oh wow, I just quickly glanced and thought that was coolant temp.Yes - what is the coolant temp? Is there an internal bypass or thermostat for the trans cooler that may have failed?

Click to expand...

My shop is saying I need a whole new transmission as there are now some other symptoms...