2018 exp max engine coolant > 240

[cwellman]

We have a 2018 exp max 4x4 with towing package that seems to overheat significantly on grades when we don’t tow anything. It’s getting up to 257 and we aren’t even using the tow features…just driving a family of 6. When we are driving on level roads it will sometimes heat up to 240 along with the transmission. FYI The tranny was completely rebuilt at just over 12,00 miles, and many things have had tech issues like media, back up cameras. We bought it 2 years old with 7k miles on it from a dealer and wonder if we got a dud. The dealership doesn’t know why it would be overheating in these conditions.

 

[cool9527]

I have the same exact issue. 2018 with 44K on the odometer. It seems to happen in 10th gear, highway speeds...when I take it outta cruise and gun it to get to a lower gear (usually 7), temp starts coming down.

Taking it in Monday to see what the dealer says.

 

[BMW2FORD]

I had the same problem cruising on the highway in top gear at about 70mph. I wasn’t towing or pushing the truck hard and it was cold outside (below 50 degrees) when it happened. I knew right away something couldn’t be right for a truck to overheat like that and either the radiator shutters or thermostat must be bad since I had no coolant leaks and the system was always full and not dropping. I started to look over the radiator shudders to be sure they opened when I turned on the AC and when the truck shut and didn’t make any sounds like they were jamming. I was afraid to take it to the dealer in case they couldn’t duplicate it since sometimes you really had to drive pretty far on the highway for it to happen so I took it upon myself to pull out the thermostat and take a look. I’m glad I did since it was clear and easy to see it was jamming with plenty of marks to prove it. I replaced the thermostat with a Ford OE part for $25, changed the coolant while I was at it to the new yellow style and it’s perfect. FordBossMe on YouTube even found that Ford has a new style thermostat with a plastic sleeve which looks to prevent this binding from happening. The Ford F-150 forums have tons of people with this problem and a lot after phaser repairs most likely since when these cooling systems are opened and bled the air pockets must take a toll on the thermostat. Here’s the link to the YouTube video,

2018 Ford F150 Overheating After Cam Phaser Replacement - Here is why

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youtu.be

I almost think after seeing the simplicity and quality of this thermostat versus the load on the coolant system that this should just be changed every few years as a maintenance item.

 

[cwellman]

Same as both of you. Thank you so much! I’ll check this out!

 

[cool9527]

Thanks bmw2ford! Makes me feel good that it wasn't too terrible.

How hard was changing the thermostat and bleeding the coolant? I'm inclined to just do it myself now.

 

[BMW2FORD]

It’s very easy. There’s a radiator drain upwards in the drivers side on the bottom of the radiator that looks like a large flat head screw to drain the coolant. Only about a gallon to a gallon and a half comes out since these radiators don't hold a lot. Then there's 3x 8mm screws that hold the plastic thermostat housing to the water manifold (T stat is on the lower hose entry to the engine on an Ecoboost which leads to the drivers side). You don't have to even take the large hose off the T stat housing and once the 3x 8mm's are removed you can flex it to the side with no problems since its rubber. The 8mm screw at about the 4pm side on the thermostat housing is a little tough to see but easy to get the 8mm socket onto as well as all the rest. I used a 1/4 inch drive set. When that's pulled, about another quart of coolant will come out with the thermostat and you will see the rubber gasket that slips onto the outside of the thermostat and comes out easily with it. Make sure if you do replace the thermostat that you get the rubber o-ring seal as well since that seals the thermostat and housing.

As far as bleeding, that's very similar to older cars but there's many more hoses and routes it takes so you just need a little more time and top off's. Best way to do that is to try to get the nose of the truck up higher if possible on a hill or floor jack. Only about a half a foot or more is good to get the reservoir as high as possible and all hoses aiming up. Fill the reservoir about an inch over the full line and then slowly squeeze the upper and lower large hoses with the cap still off and bubbles will start to run to the reservoir. Refill to about an inch over the fill line if it fell then install the cap and start the engine and turn the heat in the front and also rear if you have that to full hot. let the car run a few seconds then bring to about 2000 rpm for 30 seconds and then let it idle and while running check the reservoir level. If still over full, let it run until it falls low to re top off or let it get fully hot so the T stat opens if not falling low. If it falls before getting full hot, shut the engine and slowly remove the cap and refill a little over the full line then let it run again. Trick with these is to just keep an eye on them and re top off as the bubbles run to the reservoir if needed but with the nose higher and squeezing the hoses you most likely not even need to top it off. If its over the full line when all done, leave it there and after a few cold starts and hot shut offs it will bleed a little off from the overflow and they usually fall right back to the full line. Overflow in right under the cap behind on the engine side so don't be surprised a few days later to see some drops there.

 

[nitro nicky]

Obviously there's an issue. What we racers and motorcycle riders use is the product: 'Water Wetter' added to the fluid. I would assume it would be a perfect product to use in a very heavy truck. I'm sure you've replaced you radiator fluid every 3 or so years as allegedly fluid turns chemically on itself and will rot coolant parts. It definitely sounds like a typical thermostat issue. I've had Ford thermo's stick on one year old rigs. Do you know how to backflush your radiator? I usually use a catch basin on the first radiator flush I do with a vehicle. That way I can see any debris.
The worst thing is when a head gasket starts to go bad and the leaking compression pushes out fluid through the over flow container. Hopefully you are aware that when adding fluid to the catch bottle it's proper to poor in undiluted radiator fluid so that the bottle doesn't discolor with rust carried around in the water portion of the 50/50 mix. Nico

 

[cool9527]

Bmw2ford, what was the new part number for the thermostat that you got and was referred to in the video?

Thanks again!

 

[BMW2FORD]

FordBossMe added it to the comments of his video (he’s a Ford Master Tech) and it’s HL3Z-8575-B. The O ring is HL3Z-8255-A. I actually used the old style T stat and seen the video about a day later but an old style good working T stat is better any day that n a bad one. In about 2 or 3 years if I still have the truck I’ll replace it again with the new style.

 

[cool9527]

Welp, truck is hopefully coming home tomorrow. Turns out there was a leak in one of the hoses coming off the coolant reservoir. They found it doing a pressure test.

Hopefully that's the last of it for a while...

 

[cwellman]

Well, Ford is saying that it’s a clogged radiator. A radiator kit is not covered under warranty even though we are under 60,000 miles and it will be approximately $1300 to fix. On top of everything we’ve had to do to this lemon of a new vehicle, I think I’m done with it. They’re not even sure that it will 100% fix the issue but say it needs to be done. They’ve checked everything else I’ve mentioned from this thread and it’s all fine.

 

[mlogan]

Wonder if this applies to the 2015 Expy/earlier ecoboost - I think Gen I - looks like an upgraded part ending in B for that thermostat as well.

 

[BMW2FORD]

Well, Ford is saying that it’s a clogged radiator. A radiator kit is not covered under warranty even though we are under 60,000 miles and it will be approximately $1300 to fix. On top of everything we’ve had to do to this lemon of a new vehicle, I think I’m done with it. They’re not even sure that it will 100% fix the issue but say it needs to be done. They’ve checked everything else I’ve mentioned from this thread and it’s all fine.

That’s sad they say it’s not covered under Powertrain but what also worries me is if that’s really what’s wrong. A clogged radiator is possible but I haven’t seen that on a newer car with an aluminum radiator in years and usually it’s on a really old car. Maybe there’s debris in the front of the radiator and it’s not internally clogged on the coolant side? I’d call Ford corporate directly to see if they will provide assistance. In my opinion, when a car runs this hot it should also have the thermostat replaced with any coolant repair as well or it will usually fail shortly after if it’s really not the problem now.

 

[Soliyou]

Well, Ford is saying that it’s a clogged radiator. A radiator kit is not covered under warranty even though we are under 60,000 miles and it will be approximately $1300 to fix. On top of everything we’ve had to do to this lemon of a new vehicle, I think I’m done with it. They’re not even sure that it will 100% fix the issue but say it needs to be done. They’ve checked everything else I’ve mentioned from this thread and it’s all fine.

Take it home and change the thermostat first. I guess this will be the issue.

 

[BMW2FORD]

Take it home and change the thermostat first. I guess this will be the issue.

I agree, I’d start there or find a good independent to do it.

 

[3rd Expyowner123]

My 2018 Expedition with HD Tow package, 62k miles, had cam phasers done about six month ago. Like others, heard cooling fans running hard after running a quick errand. Opened hood, coolant was low, couldn’t see any leaks. Checked engine oil, it was fine. Took to dealer who diagnosed water pump was leaking coolant out of weep hole. Had dealer replace water pump. Drove to Colorado and engine temperature started appearing above the gauge, reading about 234 degrees when driving with my truck rather loaded with people and gear while climbing on a freeway at 75mph with air temperature around 60 degrees. Had similar experience on same trip with vehicle not loaded, driving up 7% grade at 45mph with outdoor temperature of 40 degrees.
The coolant reservoir was filled above the max line from the dealer after water pump replacement.
I have pulled my boat numerous times in 100 degree outdoor temperature maintaining 75mph, never having a problem.
Any tips or comments? I will return the truck to the dealer who did the water pump. Likely they will not duplicate the problem. Since the water pump was replaced under my Ford extended warranty, have no idea if thermostat was replaced.

 

[NC12South]

Not sure if this was discussed before, but the thermostat design has been changed and it is a major change. Check out lincoln forums to see the whole chain and more photos, but here is what the new thermostat looks like and engine data before and after. The temperature change is significant in both engine and transmission. Old thermostat on the left.

 

[wakeboarder]

Not sure if this was discussed before, but the thermostat design has been changed and it is a major change. Check out lincoln forums to see the whole chain and more photos, but here is what the new thermostat looks like and engine data before and after. The temperature change is significant in both engine and transmission. Old thermostat on the left.

I changed the thermostat as a preventative measure to the most up to date PN. It has reduced the engine and transmission temperature by about 10-15°F. Prior to changing the engine was 205 to 212° and the transmission was 200 to 210°. After changing, the engine temperature is 190 to 200° and the transmission is 185 to 195°.