Blown F-150· Premium Member
thermostat on orderI had an 8 month oem 195 stat do this to me. If I idled for an extended time, like 5 + mins temps would spike, fan would kick on high. This is in winter with 20 degree outdoor temps. If your fans are cycling high and off with little or no load, just change the stat. Its easy.
Maybe a built in bug or feature for emissions purposes or something?I like that test you did, and wonder if all the Motorcraft 195 stats are not fully open till near 217. E.g. is it a feature or a bug. Would explain a lot.
Just brought the OP up to keep me straight.I just recently purchased a 5 Star Tune for my 2018 3.5 . The temp outside was 45 deg . Yes did have to play with the 93 performance tune that night . I ran her pretty hard 130 mph plus , My coolant temp on my scanner got up to 235 pretty quick , but it dropped to 212 just as quick . I just scanned my truck a few minutes ago it had a past code for high coolant temp . Is or has anyone seen that high coolant temp with a tune and if so what did you do to remedy the situation . Yes I did notice my fans were running allot that night allot more than before . The needle gauge on my dash was only a little past the middle though .
The "bug" is that some Motorcraft factory installed 195 thermostats run in the 207-217 range instead of 195-205 range. The factory analog sweeper gauge will never show this. If someone didn't have the digital readouts over their analog gauges, they would never know about it. I think Ford is betting on that.It's definitely a feature, not a bug.
The grill shutters play a roll on the new trucks too.If they are not open you are not getting cooling air.My understanding is once your temps get beyond the Thermostat rating - whether 180 or 195 - then cooling isnt really up to the stat anymore, its all on the cooling stack.
So if you are running 'er easy maybe - maybe - having coolant flowing slightly earlier can keep temps down (idk), but I assume once you give it the whip for any amount of time, you are quickly generating enough heat to blow by either 180 or 195 or 207, and the stat is no longer a factor.
Now if the stat isn't really opening at 195 or so, then that's a more fundamental problem.
I think most thermostats take 15-20 degrees to open. Even the thermostat for my improved racing oil cooler started to open at ~200 but would land at a target temp of 215I like that test you did, and wonder if all the Motorcraft 195 stats are not fully open till near 217. E.g. is it a feature or a bug. Would explain a lot.
thank youEco mode will make it run hotter because it will stay in the highest gear possible and simply add fuel to the turbos to maintain speed, even up hills.
My factory 195 thermostat didn't actually open until around 205-207 degrees Fahrenheit. The Ford Motprcraft 180 thermostat operates closer to its labeled temp range. I installed one in my 2018 F150 3.5 and it went from a normal temp of 207-217F to a normal of 185-195F. I now only hit high spikes of 199-204F getting on it up hills whereas before it would hit as high as 223-226F.
Why some factory 195 thermostats wait to open closer to 207F is a mystery to me.
Motorcraft part # BR3E-8575-BB is a 180F unit.
View attachment 186317 .
125 mph oh my 😁Nice. I just ordered a BR3E-8575-BB to have on the shelf in preparation of running tuned, and towing my camper this summer.
Agreed, t-stats are not on-off devices, the line is blurry. And in any case, starting with a 180-190°F engine and everything else under the hood, gives you a lot more thermal capacity and buffer for the times when you rip a pull to 125mph, or hit that mountain grade with the camper in tow, etc.
The redesigned thermostat fixed my heating problem.Highly recommend OEM thermostat.
Many folks around here ended up returning to them after taking similar approaches to battling sudden higher temps.
Ford redesigned the thermostat.
The original very well could be misbehaving.
I have not received it yet . I had it ordered from one company and it was backordered 6 days after i ordered it , It has been reordered from 5 STAR . I will tell you all this my tune does make it run about 4 to 5 deg hotter than stock tune . I compared the 2 today , But the high coolant temps were there before I tuned it .I found out .Waiting to hear if the low temp stat fixes the OP issue