Upper Range of Normal Engine Operating Temperatures - What are the actual numbers from Ford?

[2020SilverFx4]

I am looking for official information from Ford on the normal engine operating temperatures. My Ranger is basically in stock form - factory towing package, Fx4, extended cab. I do have the Ford Performance shocks/struts and upgraded leaf springs in the rear.

For example, I found this for the 10R80 transmission: "200 to 235 degrees is normal. At 255 degrees the computer will log temps and then at 260 will set of a dash warning light."

I tow 4,000lbs over all the passes in Colorado, and the transmission peaked this summer at 242 degrees F, and the engine at 235 degrees F while pulling Vail pass going east. I was going the speed limit and not really trying to keep temps down. Basically climbing w/ 16 to 19 pounds of boost for many miles.

What is the max "safe" temperature range for the engine, per Ford? At 235 the engine temperature swing gauge had not moved from the middle, and at 242 the transmission performed just fine. I regularly run at 225 degrees F for both the engine and transmission in the winter. I use a ScanGauge II to view digital numbers for both.

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[RangerBill]

I am looking for official information from Ford on the normal engine operating temperatures. My Ranger is basically in stock form - factory towing package, Fx4, extended cab. I do have the Ford Performance shocks/struts and upgraded leaf springs in the rear.

For example, I found this for the 10R80 transmission: "200 to 235 degrees is normal. At 255 degrees the computer will log temps and then at 260 will set of a dash warning light."

I tow 4,000lbs over all the passes in Colorado, and the transmission peaked this summer at 242 degrees F, and the engine at 235 degrees F while pulling Vail pass going east. I was going the speed limit and not really trying to keep temps down. Basically climbing w/ 16 to 19 pounds of boost for many miles.

What is the max "safe" temperature range for the engine, per Ford? At 235 the engine temperature swing gauge had not moved from the middle, and at 242 the transmission performed just fine. I regularly run at 225 degrees F for both the engine and transmission in the winter. I use a ScanGauge II to view digital numbers for both.

From the shop manual:

Thermostat Opening Temperatures

Starts to open	92°C (197.6°F)
Fully open	106°C (222.8°F)

This doesn't exactly answer your question, but the coolant temp. can go higher than 222.8°. As long as the coolant doesn't boil, it isn't overheating. The pressurized cooling system and anti-freeze allows coolant temps higher than the boiling point of water.

See this for how the pressure in the system affects the boiling point of the coolant.
https://flex-a-lite.com/blog/how-radiator-cap-pressure-affects-cooling

 

[Dereku]

I would address the transmission temp regardless what anyone says. Start with an aluminum trans pan. If still high swap out the whe radiator. Not being a smart ass either. I would 100 percent do that if I was seeing those temps. I get it the ULV fluid handles temps better but no matter what heat kills fluid.

 

[puckdodger]

I would think if it's not logging temps you should be fine.

 

[dtech]

I would agree with the puck dodger on this , would be wise to change the fluids on a shorter interval than Ford recommends, having said that I'll admit never have looked into the manual to see if Ford has a severe maintenance schedule.
I used to drive Vail Pass and the I-70 tunnel fairly often years back and on hot summer days recall a lot of RVs and trucks towing pulled to the shoulder and overheating, but that was back when a lot of carbureted engines were common, my fuel injected turbo 1986 Saab would fly by most of that stuff headed up the passes. Nowadays it can be pretty crazy with all the high powered stuff on the road puttin pedal to the metal to get to the top of the hill before others and then you have the younger dudes in econo boxes lagging on the uphill then flying past you on the downhill.

 

[BassRanger]

Ford's safe operating temperature range is programmed into the ECU. If the truck is not intervening to cool itself down(Limp home/reduced power mode), then it's safe to assume it's operating within it's intended parameters.

People have been freaking out over the 10r80's temperatures since Ford/GM introduced it. 5 years and 15+ different vehicles, just google how many actual documented 10r80/10l80 overheating cases you can find.

Long/short; if the trucks running fine with no malfunction lights, then no worries.

 

[Jason B]

I would address the transmission temp regardless what anyone says. Start with an aluminum trans pan. If still high swap out the whe radiator. Not being a smart ass either. I would 100 percent do that if I was seeing those temps. I get it the ULV fluid handles temps better but no matter what heat kills fluid.

Why swap out the radiator if the trans has high temp? AFAIK, there is no cooling loop from trans to radiator, nor any active* cooling for the trans.
Edit: I mean external cooling devices for the trans.

 

[Big Blue]

Why swap out the radiator if the trans has high temp? AFAIK, there is no cooling loop from trans to radiator, nor any active* cooling for the trans.
Edit: I mean external cooling devices for the trans.

Swapping the radiator will do nothing for you as there is no separate cooling loop for the transmission as in the past. There is a heat exchanger on the transmission that is tied into the engine coolant circuit. Its main purpose is to help the transmission get up to temp quicker, not cool it.

As @BassRanger said people get all excited by the temp the 10R80 runs at. It is intended to run at 200+ degrees and as long as it is under 250 degrees it's just fine. Why do you think people complain about the first ships in the morning and maybe some jerkyness. It needs to warm up.

 

[Dereku]

Why swap out the radiator if the trans has high temp? AFAIK, there is no cooling loop from trans to radiator, nor any active* cooling for the trans.
Edit: I mean external cooling devices for the trans.

The high engine temps will impact the transmission due to the external cooling loop. Not to mention the close proximity to the transmission as well. Radiant heat will heat up other components. A quality downpipe wrap would help as well. That sucker gets hot. I have done all these things to trucks in the past and monitored the temps at all times.

Last truck had an upgrade radiator and trans pan. 08 f150 4.6. Transmission temps never exceeded 180 degrees when towing at the limit in 100 plus degree days.

While ULV mercon has a higher temp tolerance, pushing close to the limit is still not good for the long term.

 

[2020SilverFx4]

Good info in this thread so far, thanks much.

For what it's worth - I don't have much concern on the transmission temps - the 10sp in my work F-450 runs at 235 to 245 all the time (it's always towing or has a massive load on the flat bed). It's just over 150k miles and has been serviced at 50k and 100k and 150k with a full flush from a Ford dealer. I plan to do the same w/ the Ranger.

I was more curious on the engine temps - but if the swing gauge doesn't move when it's at 235, I definitely have some degrees to go before backing out of the throttle. I have faith that Ford engineered the gauges this way for a reason, so absent of an aftermarket temp gauge reading OBD2, I would think all was 'normal' (which is what it looks like at this time).

Yes, times have changed. My 2000 F150 engine/transmission never went above 195 degrees F while towing (after I added a trans cooler the size of a Subaru radiator and a 4500 CFM fan), and my 2008 F250 transmission sat at 215 degrees F regardless of what I did to it - loaded or unloaded. Both went over 200k with no failures and normal 30k mile service intervals.

 

[Justin says...]

Just curious how you are seeing your trans temps? Is this something I can enable with Forscan or something?

 

[2020SilverFx4]

Just curious how you are seeing your trans temps? Is this something I can enable with Forscan or something?

https://www.scangauge.com/support/x-gauge-commands/ford-lincoln-mercury/

and

https://www.scangauge.com/

 

[dtech]

Good info in this thread so far, thanks much.

For what it's worth - I don't have much concern on the transmission temps - the 10sp in my work F-450 runs at 235 to 245 all the time (it's always towing or has a massive load on the flat bed). It's just over 150k miles and has been serviced at 50k and 100k and 150k with a full flush from a Ford dealer. I plan to do the same w/ the Ranger.

I was more curious on the engine temps - but if the swing gauge doesn't move when it's at 235, I definitely have some degrees to go before backing out of the throttle. I have faith that Ford engineered the gauges this way for a reason, so absent of an aftermarket temp gauge reading OBD2, I would think all was 'normal' (which is what it looks like at this time).

Yes, times have changed. My 2000 F150 engine/transmission never went above 195 degrees F while towing (after I added a trans cooler the size of a Subaru radiator and a 4500 CFM fan), and my 2008 F250 transmission sat at 215 degrees F regardless of what I did to it - loaded or unloaded. Both went over 200k with no failures and normal 30k mile service intervals.

Yeah it's generally thought the programing of the gauges is intended to not cause worry when there are minor fluctuations, enough to show that readings are in or out of an acceptable range . And yes things have changed markedly from yrs back in the ability to be very precise in designing things like cooling systems with respect to heat transfer, water pump design, flows, etc. And as Phil points out all this goes thru rigorous testing, amazing the evolution of the ice , too bad though it still cant come anywhere near the efficiency of the electric stuff.

 

[Jason B]

Yeah it's generally thought the programing of the gauges is intended to not cause worry when there are minor fluctuations, enough to show that readings are in or out of an acceptable range . And yes things have changed markedly from yrs back in the ability to be very precise in designing things like cooling systems with respect to heat transfer, water pump design, flows, etc. And as Phil points out all this goes thru rigorous testing, amazing the evolution of the ice , too bad though it still cant come anywhere near the efficiency of the electric stuff.

On many vehicles, the gauges are actually gauges, more so an indicator tied to a switch. EX: my F150 oil pressure 'gauge'. If you had pressure, it would indicate normal, below a certain threshold, it indicates no pressure. Same with the temp gauge, although I think it was in steps. low, normal, high, overheat. Those gauges were not a gradual swing representing varying pressure and temps.

 

[Grandaccess]

2021 XLT at around 13k miles I blew a lower Rat hose 4 months ago it had rubbed on an edge of the frame, just a slice but these trucks have a good Brain, it let me know fluid was low, then as it over heated the truck reduced power then it went into some strange Limp home mode and would only let me do 5 MPH, but way before any damage it will turn your truck off and it did because I was 5 miles from an exit, its probably not a good thing to do often because head gasket and other things that would be stressed...
I use a bluetooth dongle and a 12.2 samsung tablet to monitor different things, and have made different screens for city highway and towing
this is a catch all screen of the strange ones I watch
look at the fuel rail pressure LOL I am use to seeing 17 to 45 PSI in some of my old ass P.O.SI was like NFW

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