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Great post. Does this thermostat post apply to 2015? I have a 2015 F150Eco 3.5 with 150K miles and recently was experiencing some high temps under load such as towing or long, steep climbs at speed. I've replaced the radiator with a bigger one, new ford water pump and Duralast thermostat (I know, I already ordered a Motorcraft replacement). Now I am having bigger heat problems, getting high 230+ temps with just normal driving. HELP!!
Had looked for sometime for remedy to this issue. Problem started as the cooling fans coming on as I was slowing down. Once stopped fans slowly wound down then quiet. This issue started at approx 69,000 miles. Next i noticed im driving along at 60 MPH and the fans are running on high speed most of the time , although its 35 degrees out. Temp gauge always steady at halfway point or slightly left. Contacted numerous dealers and most said they never heard of this issue which is odd since the internet has endless sites for various concerns. I even recorded what the fans were doing with Dealer VCM 2 system and was told by Ford Tech Service that the system was operating as designed and no faults were detected. Also found 2021 had a different thermostat as shown in your picture but they stated 2021 had the same and they have not changed its design... bull. Long story short i replaced the thermostat with new per this thread and it now is working properly . Thanks for help
I joined this forum because I am so grateful for the information I found regarding replacing the thermostat on my 2019 Ford expedition. I am on a long road trip towing a 23 foot Airstream travel trailer whose dry weight is 5000 pounds. The engine had been running hot for weeks, with the digits frequently drifting up to 230 to 235, and sometimes 237 or 239, then the temperature would fall back down below 228 when the digits would disappear, only for the whole cycle to repeat again a few minutes later. I just had the thermostat replaced, and yesterday I towed all day in hot weather on the interstate with the air conditioner on, and the temperature digits never showed, i.e. the engine ran cool all day. What a relief! Thanks so much. BTW, I talked to several Ford service departments, and no one seemed to be aware of this issue. The parts department guy said that Ford had changed the number of this part, but I believe this means they changed the part itself, as several of you have indicated. I imagine Ford does not want to draw too much attention to this issue, but I think they would’ve been better off issuing a notice of some kind, as their inaction produces resentment among we owners and makes you want to give the other makes another look next time.
There are some F150 owners here who might have experienced some overheat or surge temperature issues. These issues have now been completely solved by Ford with a change in thermostat. BTW, this issue also applies to the Ford Expedition/Lincoln Navigator which have similar 3.5 liter Ecoboost engines. There are some tricks that F150 owners used in the past to resolve the issue such as switching to a 170 degree thermostat or disconnecting the active grille shutters. You will not need to do that anymore with this fix. Reconnect the shutters and dont bother with aftermarket thermostats. This is a complete fix.
The name of the new Ford thermostat is the RT-1252. It has a black end and no gasket on the back as you can see in the photos attached. I put the stock thermostat on the left side and the new RT-1252 on the right side. The main problem causing the overheating issue was the the thermostat was sticking closed but the newly redesigned thermostat no longer sticks closed.
So if you have a 2017-2020 Ford F150/Raptor, 2018-2021 Ford Expedition or 2018-2021 Lincoln Navigator and are finding your truck running too hot then this will be the fix. My truck ran at around 210-220 degrees with the stock thermostat and would surge way past 220 degrees during high demand times. After my truck runs from 200-210 degrees and I cant get it above 212 degrees no matter how hard I tried.
I just joined this site by the way to share this information. I dont participate in websites. This issue has been ******* me since 2018 and I wanted to spread the word on the exact fix for those that need it. Also other things which help keep temperature in line are using the Motorcraft air filter( forget about aftermarket), changing the spark plugs before 50000 miles with the stock Motorcraft plugs...check for most current plug suggested by Ford, and removing the engine cover...serves no other purpose but to dress up engine. However, the main issue is the thermostat.
After the thermostat is changed you can go back to the stock cooling setup to include connected grille shutters. You wont need to do any more cooling tricks after this fix.
