Well, another oddball part for the Jeep! It doesn't look like it, but it's got a few tricks up its sleeve.
This thermostat from Mishimoto. For anyone who has ever seen the price tag on these: Yep, I took one for the team. I had to do a coolant flush anyways, so I figured I'd pick this bugger up, and move the old one to reserve duty. Ultimately, I wasn't terribly impressed with the Jeep's cooling performance as of late. Under load, the needle wallows up past the nominal 210, and anyone whose had one of these rigs knows what things a hot running 4.7l are prone to. I figured, at best, I cool down and stay cooler (This is supposed to be a high flow thermostat?), and at the worst, I have a thermostat with a lifetime warranty.
This Thermo also opens at 180 degrees, as compared to stock's 195. It's also supposed to have a higher flow rate, however I suppose time will tell. It looks pretty similar to an OEM Thermostat, though the "cage" on the back containing all of the actual workings is fairly larger, and looks like it probably allows the mechanism to open further than a stock one.
As for the coolant, I put Zerex G-05 in it. It's the only non Mopar HOAT that is recommended for this engine. I also put a shot of Lucas Super Coolant in it, as it has corrosion & electrolysis inhibitors. It also claims to make the heat transfer process more efficient, we'll see about that in the hot months.
The fact of the matter is, with this engine, anywhere between 190-210 is considered "nominal." If it gets too much further below 190 or 180ish, the PCM will complain that the engine is staying too cold. In my case, this combination leads to a running temperature right about 190, and it moves towards 210 under load. Previously, it ran at about 200 or 210 normally, depending on the air temperature (summer days are like driving in a giant hair dryer) and as high as 220 under load. It doesn't seem like a crazy high number, however anything over 210 can be extremely detrimental to the life of this engine. There's a chance the aluminum heads can warp, or you can even drop a valve seat and chew up a cylinder pretty quickly. Maintaining a good cooling environment is critical to the life of the engine.
Otherwise, today she got another new TPS, the 3rd in the last 4 months. I suspect it would be wise to get a mopar sensor in the future. For now I'll keep milking AutoZone's Lifetime warranty.