Thermostat thread

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TwizzleStix

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Yes! 170 is a bit too cool for the interior heater to work well. 180 is perfect IF you set the various grill & intercooler shutter, fans, and several other cross-over points in the tune to account for the cooler engine temps. The factory Desired Operating Temp is 210 degF

So, I installed a 180 degF t-stat in my 2018. Note the oem t-stat removed is a 95”C” temp which is actually 203F which is a most common temp in all the vehicles in the last decade or so. The oem target temp is 210F so the fans DC is setup for that value. I tweaked the target down to 195F and the fan DC/temp delta response up to drive the fans harder-sooner.

Note that the FMIC fan controls are now available in Cobb AT. You can adjust the Cooling Demand targets and the related IC fan DC response. These new controls are only applicable to the stock or stock replacement IC, obviously. There’s still something missing in the controls though...
 

zemuron99

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Well, I (tried) installing my SPD t'stat today. Man that drivers' side bolt is a PITA. Didn't use a deep socket (my smallest 3/8 drive is 9mm) so had to use a long-handled 3/8 w/a universal joint on the end to get it loose enough to turn by hand. Don't ask how much fun that was. Anyway, put the new t'stat in, buttoned everything up (after remembering I have a 1/4" drive set that has an 8mm deep to do the drivers' side), fill the coolant bottle...and hear the waterfall. *&^%$#@!. Housing is leaking, looks like from the bottom, obviously I've not got the t'stat aligned properly, and the 3mm added length caused it. (Yes, I have the o-ring on, and yes I have the brass spring side in the block, so that's not the issue). Pissed out roughly half a gallon of my coolant concentrate, but that's a secondary concern, I still have a half-gallon left. Took it all apart, the O-ring looks okay, no pinched sections or break in it, so if I get it all together correctly it should work ok...right?

BIG question: Hints and tricks to get it back together properly aligned from those that have done it? I saw one thread where the member replaced the stock bolts w/some threaded studs and nuts on those, and used those as the guide to getting the housing back, but c'mon there has to be a way to do it w/the stock bolts. So help a brother out here, and give me your best trick for getting it all lined up and back together!
 

titanjc

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Well, I (tried) installing my SPD t'stat today. Man that drivers' side bolt is a PITA. Didn't use a deep socket (my smallest 3/8 drive is 9mm) so had to use a long-handled 3/8 w/a universal joint on the end to get it loose enough to turn by hand. Don't ask how much fun that was. Anyway, put the new t'stat in, buttoned everything up (after remembering I have a 1/4" drive set that has an 8mm deep to do the drivers' side), fill the coolant bottle...and hear the waterfall. *&^%$#@!. Housing is leaking, looks like from the bottom, obviously I've not got the t'stat aligned properly, and the 3mm added length caused it. (Yes, I have the o-ring on, and yes I have the brass spring side in the block, so that's not the issue). Pissed out roughly half a gallon of my coolant concentrate, but that's a secondary concern, I still have a half-gallon left. Took it all apart, the O-ring looks okay, no pinched sections or break in it, so if I get it all together correctly it should work ok...right?

BIG question: Hints and tricks to get it back together properly aligned from those that have done it? I saw one thread where the member replaced the stock bolts w/some threaded studs and nuts on those, and used those as the guide to getting the housing back, but c'mon there has to be a way to do it w/the stock bolts. So help a brother out here, and give me your best trick for getting it all lined up and back together!
I went through the exact same thing a couple of weekends ago, right down to wasting half a gallon of coolant! I couldn’t get the square-edged SPD o-ring to sit properly within the opening, so I ended up re-using the factory Ford o-ring. It went on perfectly the first time, and I’ve had no leaks or issues in daily driving it for the last 3 weeks. Temps now don’t get any higher than 183 or so before quickly dropping back to the mid 170’s, and that’s in Florida summer heat. Good luck!
 

zemuron99

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I went through the exact same thing a couple of weekends ago, right down to wasting half a gallon of coolant! I couldn’t get the square-edged SPD o-ring to sit properly within the opening, so I ended up re-using the factory Ford o-ring. It went on perfectly the first time, and I’ve had no leaks or issues in daily driving it for the last 3 weeks. Temps now don’t get any higher than 183 or so before quickly dropping back to the mid 170’s, and that’s in Florida summer heat. Good luck!

Thanks, I did re-use the stock o-ring, there wasn't even one in the box of my t-stat. Maybe a fresh attack today will give better results. Appreciate the reply! Def looking forward to the lower temps, even though we're quite a bit cooler up here in the "Left Coast".
 

Booth9999

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I went through the exact same thing a couple of weekends ago, right down to wasting half a gallon of coolant! I couldn’t get the square-edged SPD o-ring to sit properly within the opening, so I ended up re-using the factory Ford o-ring. It went on perfectly the first time, and I’ve had no leaks or issues in daily driving it for the last 3 weeks. Temps now don’t get any higher than 183 or so before quickly dropping back to the mid 170’s, and that’s in Florida summer heat. Good luck!
Did you have to get a tune after the new thermostat install? Getting ready for my install thanks!
 

titanjc

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Did you have to get a tune after the new thermostat install? Getting ready for my install thanks!
No, you don’t have to, but I have read that it is a good idea to have your tuner program your fans to come on at the lower temperature as well. I’m running a Stage 2 GooseTuned 93 octane tune (highly recommended!!!) and will probably update it for the fans at some point.
 

nikhsub1

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Did you have to get a tune after the new thermostat install? Getting ready for my install thanks!
As posted above, you don't have to. Basically, at speed the truck will run in the 170s and 180's normally. If you don't program for the fans to kick on earlier they will kick on when the OEM temp is, which is around 220 I think. Of course, you will only reach these high temps at idle. If you get your tuner to do it they have the fans kick on around 185 ish im pretty sure.
 

zemuron99

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(Cross posted in SPD 170 Thermostat thread).

Well, 2nd time was the charm! Won't even BEGIN to describe the un-dignified position I was in, draped over the passenger fender. Popped the t'stat in, used a small flat-blade screwdriver to hold it in place until I could get a grip on the housing cover and mostly position it. Slid the screwdriver out as I held the housing in place with my left hand, and hand-threaded the bolts in by hand then sockets. Went one-by-one tightening a bit more each time just to keep pressure even. Filled it up, heard it burping a few times but no leaks. Stared her up, let her get warm to 180 or so and it was bone dry. WOOHOO. Too pooped to even take a quick spin round the neighborhood, will save that for another day. Thanks for the support and encouragement everyone!
 
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