Engine temp spikes on highway

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

keny01998

Full Access Members
Joined
Aug 31, 2019
Posts
192
Reaction score
84
Location
Arkansas
For a long trip over 10 hours, I usually got engine temp over 230 for 1 minute or 2, sometimes it went up to 235 but went away. My trans temp went up to 217-220.
 

2020ExpyPlatinum

Well-Known Member
Joined
Aug 4, 2020
Posts
57
Reaction score
28
Location
Cleveland, OH
I would guess there is air trapped in the system possibly. Some vehicles have a very specific bleed procedure to get the air out.

If it is not air in the system is it possible the automatic louvers are acting up behind the front grill? I know on our expedition it has computer controlled louvers that open or close depending on the vehicle temperature.
 

byathread

Full Access Members
Joined
May 8, 2019
Posts
216
Reaction score
136
Location
Pennsylvania
My 2019 will, at certain points, show the coolant temp when it reaches that threshold, usually noticed it after heat soaking events like max throttle while towing or driving the piss out of it (hard acceleration uphill on the highway, etc.). It shows upwards of 238 or so and then recedes, basically due to the thermostat opening lag and coolant flows, is what I always thought... Normal, no leaks I'm aware of and has been doing that since new. Currently at about 46K... Even at 240-242 briefly, it's probably fine/not cooking it/within tolerance. I remember seeing 238 or 240 once and the gauge turned amber then went right back to blue. Unless there is clear evidence of a leak, then, just drive it is my $0.02...
 

Artie

Full Access Members
Joined
Jul 24, 2017
Posts
1,870
Reaction score
1,033
Location
Georgia
Reading through this thread I’m wondering if not purging the cooking system could have caused my transmission temperature spike. Does anyone know if the transmission has its own completely separate cooler or does it share with the radiator?
 

wakeboarder

Full Access Members
Joined
Nov 16, 2019
Posts
757
Reaction score
431
Location
Fort Lauderdale, FL
Reading through this thread I’m wondering if not purging the cooking system could have caused my transmission temperature spike. Does anyone know if the transmission has its own completely separate cooler or does it share with the radiator?
It uses coolant from the engine’s radiator. There is a heat exchanger under the transmission.
 

Soliyou

Full Access Members
Joined
Jun 15, 2019
Posts
440
Reaction score
249
Location
OK
These engines can be difficult to bleed properly. A trapped air bubble may cause a spike in temperature and high pressure that can lead to leaks.

The shop manual only recommends using the vacuum fill procedure for the coolant.

The old style thermostat is also known to fail and cause slight overheat after coolant change.
 

wakeboarder

Full Access Members
Joined
Nov 16, 2019
Posts
757
Reaction score
431
Location
Fort Lauderdale, FL
These engines can be difficult to bleed properly. A trapped air bubble may cause a spike in temperature and high pressure that can lead to leaks.

The shop manual only recommends using the vacuum fill procedure for the coolant.

The old style thermostat is also known to fail and cause slight overheat after coolant change.
My shop manual has both vacuum fill and without a vacuum fill. I followed the manual with the front uphill and on ramps. I also squeezed the coolant hoses. I have towed since then and haven’t seen any bleed issue. If I remember correctly, the bleed procedure takes 1/2 hour to 45 minutes.
 

Soliyou

Full Access Members
Joined
Jun 15, 2019
Posts
440
Reaction score
249
Location
OK
My shop manual has both vacuum fill and without a vacuum fill. I followed the manual with the front uphill and on ramps. I also squeezed the coolant hoses. I have towed since then and haven’t seen any bleed issue. If I remember correctly, the bleed procedure takes 1/2 hour to 45 minutes.
Honestly I didn’t see the other procedure in the manual, but the manual is huge!

I am referring to the flush instructions shown below:

22284146-FD03-4921-A074-B2BFEC672E38.jpeg
 

3rd Expyowner123

Full Access Members
Joined
Apr 7, 2018
Posts
142
Reaction score
33
Location
78504
My 2018, at about 70k miles began showing temperatures above the temperature gauge about a year ago when driving 85 mph on the freeway or pulling our boat at about 70 mph. (beginning to over heat). This is not a normal condition. (Mechanic at my Ford dealer agreed).
For my truck, the fix was replacing the thermostat. I spoke with two different Ford advisors at two different dealers who both stated that thermostats do not commonly get replaced. I paid for the repair (approx $320) and have not had any temperature indication above the gauge since.
In terms of repair history, earlier my truck had weep dripping from the water pump and water pumped was replaced under my Ford extended warranty. Moral of the story, replace thermostat whenever changing water pump.
As I type my truck is having heater hoses replaced, as one began with a slow leak. This repair is not included under my extended warranty.
In November dealer replaced the cam phasers under warranty. I have seen other threads here regarding heater hose connector leaks after cam phasers work. Although I do not know if the two are related.
 

Latest posts

Forum statistics

Threads
53,391
Posts
500,598
Members
46,798
Latest member
geovanni
Top