Thanks for giving us a ring, we have a pretty impressive CSR team and they are always eager to provide assistance. Let us know how everything works our, sorry for the inconvenience!

Looking forward to your results!

 

I've read through much of this thread and I still don't understand why I would want this thermostat. What is the benefit of this vs the factory stat? I fight hard to keep oil temps down, why would I want a hotter coolant temp running through the oil cooler? Same with the transmission. Then on top of it, this costs more than an OE stat and doesn't come with a new housing or oring. I must be missing something really important for a thermostat to make a 37 page thread.

 

Hotter Diesel engine = better mpg

Josh

 

Being a former 7.3 guy, you should remember the Diesel Site 203* thermostat. Same thing, The hotter the engine runs, the better it's able to burn fuel. This especially benefits tuned trucks with the additional fuel they're dumping due to tuning.

I've waited a good long while for someone to develop such a thermostat for the 6.0 and Mishimoto has. Since installing it, my truck runs noticably better and temps do not exceed 200-2004 degrees cruising, my mileage is also up 1 mpg, and I see less smoke under WOT which in and of itself is proof the thermostat does what it says it does. With the stock thermostat that wouldn't exceed 188 degrees, my truck would belch out black smoke at WOT, the 14 degree difference between the stock and Mishimoto is worth it.

 

You guys beat me to it....X3

 

Well.....being that it's still dark outside and I can't sleep, I pulled the new Mishi out of the box, installed it in the C91 housing and sure enough there's the small gap that doesn't seal up. A little boiling water took care of that, but being the engineering ignorant soul that I am, why would hot water make it close THEN open, and how can I repeat the original position of the new thermostat for the RT-1169 housing that's on the truck already?

 

The boiling water causes it to open, then when it cools, it seals. Because it's shipped with no housing, there is nothing for the spring to push against. (Which would be the pin and tab holder thingys)

It should go in the RT housing just fine now.

EDIT:I didn't realize the BPD oil cooler maintained the eot that low. Will be interesting to see if there is a change in your eot. (I'm thinking eot will be the same....hurry and install it!)

 

Wow, The new one is on it's way! And I didn't make it easy on your Customer Service dept.
Thanks Mishi!

 

Good stuff

 

It should go in easily. Even the OEM thermostat pin will protrude a long way when boiled outside of the housing.

AFA the BPD oil cooler goes, I have one of the first cold weather kits and the thermostat has given up in the oil cooler. The design has since been changed and improved on the thermostat but in order to "fix" it I have to change the whole thermostat housing which is a real PIA that I just don't have time to do. The older thermostat just isn't available anymore (for obvious reasons).

 

Well, I got the little jewel installed (what a joy that is on my truck).

Ambient air temp was 41*. SGII reported both sensors as 48* (14 hr. cold soak). Started the truck and let it idle until the temp "maxed" out at 152/132. Took it for about a 10 mile drive with the first 5 at 35-45 mph to warm the rest of her bones and it was in town. Hit the 65 mph zone at 190* and within less than a mile the thermostat opened at 204. Immediately dropped to 193 and maxed out at 200 until everything got fairly evenly warmed up. Holds at 198-200 and although I didn't drive enough to get the oil completely warmed up the oil temps were up 5-7 degrees from what they normally are. I'm currently waiting for a cool down so the coolant level will stabilize and I can finish topping it off.

The only thing I didn't like about the thermostat was the supplied gasket. Seems a little thin but after a little persuasion I managed to make it stay in the housing for the install. No leaks so far.

 

I ordered the Mishimoto MMTS-F2D-03H from amazon and it didn't come with an o-ring. Emailed Mishimoto customer service and they sent me one quickly by US Postal Service.

I bought a new RT-1169 complete thermostat and housing from Ford and removed the thermostat.

Just placing the Mishimoto thermostat in the new housing with the pin in the receiving cup, the flange does not seal. The wing retainers are about 3/4" above the clips on the housing.

It takes a small amount of effort but the thermostat wings can be pushed down to slip into the housing clips. At first I thought it wouldn't go, but with some wiggling I got the wing and spring to clear the wider brass barrel. Part of the reason this first appears difficult I believe is because the winding of the spring on the Mishi decreases in diameter towards the wing and so it may get hung up as it tries to move past the wide barrel.

I put it in a pot of boiling water for about a minute or two. Took it out and the plate sealed up tight to the housing.

Off to install it in the truck and hopefully all will be well.

Thanks to the others who put all the time and effort into assembling the info and documenting the headaches for the community.

 

My oil temps didn't get to 190 but they are up about 15* cruising around town from what they were. Haven't been able to get out for a long cruise to see what it's going to be on the highway but I'll find out Christmas eve when I head home.

 

Thanks for chiming in guys! As mentioned, the hotter temperatures will allow for improved combustion which will result in a smoother running engine, improved efficiency, and increased fuel mileage.

If you live in a warmer climate, tow heavy loads, or have issues keeping temperatures within reason, our low-temperature thermostat is set to activate at 185°F compared to the stock 192°F. That should help keep temperatures a bit lower for a truck experiencing this particular environment/operation.

Let us know if you have any additional questions!

Thanks

Great! Let us know how the installation goes.

Great to hear you had a successful install. Thank you for the feedback regarding the o-ring.

Thanks for the order, and for chiming in with your findings.

Great, looking forward to your results.

 

thanks for the update..