ever since the weather has started getting cold up here the past week my jeeps temp gauge has almost looked like it’s broken the way it doesn’t move out of the lowest temperature range. The thermostat is only about 3 years old, but I’m pretty sure it’s the culprit. Heat is also blowing cold. My question is for cold climate, should I use a lower temp thermostat, like 160 degrees? What does everyone recommend?

 

We used to go with a slightly higher temp thermostat in the winter and a lower temp in the summer.

 

So something like a 195 degree would be better for cold climate than 180/160?

 

Yep, You want them to open later in the winter and sooner in the summer.

 

Get an IR thermometer and point it at the thermostat housing once the engine is warmed up, to make sure the gauge hasnt gone bad.

 

Very good suggestion. But this is the time of year when it is common for T stats to stick open or closed so I think he is probably on the right track. And if it is 3 years old it would be good preventative maintenance just to change it anyways. I'm sure some crud has built up on the shaft in 3 years?

 

You should use a 195 degree thermostat year round in all climates. A thermostat that opens earlier in the summer really won't affect operating temperature at all in an XJ. It will only serve to reach maximum flow through the system more quickly as it warms up.

 

I stand corrected because you are right. If's it's a 4.0 they like to run at 210 most the year no matter what temp thermostat you put in them. lol

 

Right. If you actually have some cooling overhead (unlike XJs!), it could lower your overall operating temp, but then you might run into efficiency issues with computer-controlled vehicles unless you alter the fuel curve.

 

I think they made them run as hot as possible so that they could pass emission output standards.

 

Aftermarket are junk. Spend $10 more and get a Mopar, and you won't have to worry about breaking a thermostat housing again in a year.

 

You just made a very important point here. The housing... They always tend to get pulled in at the bolt flanges. It doesn't hurt to take a good file and flatten these a bit on the mating surface so that you get good even universal pressure on the gasket all the way around.