How is it not fitting? Can you post a picture? Some guys had to put it in a pot of hot water to get it together, if I remember right.

 

wanted to give an update, I ended up installing the mishi. Temps seem to sit right around 196-202 but it has Ben 60* or cooler around here since I installed it. Deltas seem to be staying around a degree closer at between 6-9 depending on if I'm highway or city. Very pleased with the mishi so far!

 

The rod that drops into the little holder on the housing is too long. This is not allowing the thermostat plate to sit flush with the beveled edge on the housing. lol get some pictures up.

 

I had the same problem genius - after boiling it in the housing though it figured itself out

 

I originally was going to have a shop install mine while they were doing my HG but they said it wouldn't fit. I later tested it in boiling water before I tried to install it and found that it did fit. I would try boiling it in water and see if that doesn't reset the sleeve in the wax of the tstat rod. A lot of them had issues due to the tstats getting hot during shipping or being stored in a warehouse prior to shipment that caused them to partially open up and not allow the wax to fully relax back to a fully closed position.

 

So put it in the housing then boil? Or boil it then install in the housing?

 

Either way, it doesn't matter. Boiling it gets it up to temp and opens it all the way up then when it cools it will reset and close all the way. It doesn't fit right now bc it is not fully closed. The wax inside has to be heated to allow it to fully open so it can then relax again and fully close.

 

Well I put it together and boiled it. I'll put some pictures up in a bit. It ended up seating when the water hit 196ish. I let it boil until it opened and its cooling off now

 

Before boiling.


During with it opening up


After with it seating correctly

 

I took a shot based on being told by a Mishimoto rep that it would fit into the Mishimoto billet housing, which is pretty much the same as the Sinister Diesel housing. It fit into the Sinister Diesel thermostat housing I have, will install in truck (hopefully tomorrow) to make sure it works.

 

I guess it's no wonder now why Ford's new thermostat comes with a new housing.

 

For those few who were asking, the Mishimoto 200 thermostat will work in the Sinister Diesel thermostat housing. I installed it this evening, went for a test ride and it got to ECT 200 and sat there, EOT was 205.5.

Very happy with it, I replaced a stock thermostat that held 192 for a whole 4 months after replacing my oil cooler and I haven't been able to get it above 184 since. I definitely recommend the Mishimoto thermostat over an OEM.

 

Glad to hear that on the Sinister housing. I am thinking of picking one up, no I can with confidence.

 

Put in a new OEM stat in the spring as the previous would not get warmer than 180*. I purposely put in the OEM one rather than this one to get the new housing knowing it wouldn't last too long, but it wasn't much more expensive. That got me to 192-193*. After a 2000 mile journey I just returned from, the temps are 188*. So that stat is on it's way out. Of course it was less than 30* outside the whole time, some days were less than 10*.

For me, this truck is for pulling. I pull hard all summer, 10K fiver with a trailer full of ATV's or jet ski's behind that on the Colorado mountain passes. Will the Mishi stat be ok for summer use for me? Or would I be switching it out. Reading through some of this thread, it sounds like some don't like it for summer, some do.

I've also noticed my mpg went down a lot when the first stat fried, then went up with the new, but not all the way back to where it started. I was kinda hoping this might get me back to where I started. 18-20ish on the highway not loaded. On this last trip I got 16ish at 75mph. I have no tunes BTW.

 

I haven't towed heavy with it since I just installed it, but I can't imagine that if your cooling system is in good shape that this thermostat would be a problem. Perhaps your fan would be more likely to come on vs a stock thermostat when towing with a heavy throttle up a mountain, but if the engine temp goes skyrocketing then something is wrong. If you're not having a problem with temps doing that now you shouldn't with the Mishimoto, either.