Erratic Coolant temps?

[goblues38]

not normal. my 2018 with 35,*** miles and a tune with stock thermostat.

My temps run 198-218 and go up and down on a cycle @ 75mph. constantly bounce in that 20 degree range. If i drive it HARD and do a 0-100 pull, or stomp on it while on the highway....it will shoot up to 230-235. But as soon as I go back to cruise speed of 75 or just no longer load the motor, it will drop back to low 220's in 15 seconds, and back to the 20 degree range 198-2018 with in 30 seconds.

 

[SVTLOPEZ]

Thermostat could be sticking or and air bubble in the system. Food for thought: Living in SoCal and traveling to the Colorado River and Baja I see temps upward of 126 degrees with long freeway hillclimbs (sometimes towing) frequently, so.......soon after purchasing my 18 and discussing my disdain for the shutters with the local Ford dealer they informed me that Ford told them (dealer) on a couple of hot running trucks to actually remove the shutters (true story). Anyway I installed a 170 thermostat and removed the shutters and turned on the temp numbers above the gauges. Immediately after install I saw erratic temps. So i parked the truck on an incline and opened the coolant reservoir and turned on the heater then brought the truck to temp. It helped but had Ford check it out anyway because they told me there could still be a air bubble in there still because there are a couple of valves in there that if you don't open up at the same time you won't properly purge the system. Ford checked it out at my oil change and said all good. Well after after 30K miles of driving on the 170 thermostat the truck runs at 196 at freeway speeds, a little more passing or hills then right back down and if you coast down a hill or come to a stop the temp will drop to almost 170 but once your back on the throttle back to to 196ish quickly-(I never changed when the fans come on). Driving in temps plus 110 degrees and I see 201-203 with drops below 180 if coasting, but right back up when on the throttle again. Sorry for the long post hope this helps, also the numbers above the swoop gauge tend to show a wider difference in temp then represented in the swoop indicator.

So is that how you purge out the air in the coolant system? Incline and heater on? So you have to open the coolant reservoir?

 

[JefferyGT]

Blown head gasket? Have you consumed any coolant?

 

[SVTLOPEZ]

Blown head gasket? Have you consumed any coolant?

No. It’s still full

 

[Sbags]

Bumping this thread back up. In 60 degree weather after driving for 20 minutes, and going up my small hill, i see temps above 220, got up to 225. And when I take an hour drive on the freeway in 70 degree temps, I'll see occasional blips above 230. But the truck hovers around 215 in normal city driving.

This all started after dealer recently fixed an oil leak and the cam phaser issue, but keeps telling me they can't replicate my temperature issues. Fan also runs constantly. I'm hoping that it's an air bubble in the system, but they pressurized the system to test for leaks, I'm hoping that would have purged any air bubbles but still seeing the problem.

Is anyone else experiencing resistance from the dealer that temps above 220 are not normal? Or am I going crazy.

 

[1BAD454SSv2]

Bumping this thread back up. In 60 degree weather after driving for 20 minutes, and going up my small hill, i see temps above 220, got up to 225. And when I take an hour drive on the freeway in 70 degree temps, I'll see occasional blips above 230. But the truck hovers around 215 in normal city driving.

This all started after dealer recently fixed an oil leak and the cam phaser issue, but keeps telling me they can't replicate my temperature issues. Fan also runs constantly. I'm hoping that it's an air bubble in the system, but they pressurized the system to test for leaks, I'm hoping that would have purged any air bubbles but still seeing the problem.

Is anyone else experiencing resistance from the dealer that temps above 220 are not normal? Or am I going crazy.

Fans should not be running constantly especially in 60 deg air. If it didn't do it before oil leak fix. They did something wrong.

 

[Sunchild714]

Bumping this thread back up. In 60 degree weather after driving for 20 minutes, and going up my small hill, i see temps above 220, got up to 225. And when I take an hour drive on the freeway in 70 degree temps, I'll see occasional blips above 230. But the truck hovers around 215 in normal city driving.

This all started after dealer recently fixed an oil leak and the cam phaser issue, but keeps telling me they can't replicate my temperature issues. Fan also runs constantly. I'm hoping that it's an air bubble in the system, but they pressurized the system to test for leaks, I'm hoping that would have purged any air bubbles but still seeing the problem.

Is anyone else experiencing resistance from the dealer that temps above 220 are not normal? Or am I going crazy.

My 2018 was doing this. Turned out my water pump went out. I had the dealer replace it. Problem solved.

 

[Sbags]

Thought I would close the loop on this one for me in case it helps someone else. I've heard of tons of people with high coolant temps after the VCT repair. I had taken the truck to the dealer two times for this issue after the VCT repair and their response was: it hasn't pulled any codes, so it's fine. And according to them, it was normal for the truck to operate at 230 degrees in 20 degree weather driving around town.

As mentioned, this all started after the cam phaser repair, so I thought it was maybe an air bubble. I followed the Ford protocol for bleeding the coolant system twice to see if the dealership somehow left an air bubble in it. No help.

I decided to replace the thermostat myself. Perhaps it was all a coincidence and the thermostat was failing after five years. The fan was running 100% of the time I was driving, which didn't happen for the first four years I owned the truck.

I went with a 170 degree SPD performance thermostat. Engine runs perfect now at 185-205, even when in sport mode on a hot day with full throttle up at 15% hill. I've heard that these engines need to run hot, but having the two stage fan running in all conditions is not right, especially given I hadn't experienced that for the first four years of ownership.

Hope this helps.