Thermostat

 Hey Shad,

Any recommendations on the degree of thermostat that I should use in my Rubicon? 165 / 180 / 195 ?????

JD

 JD,  Are you changing the thermostat for a reason? Is yours failing or sticking? Your factory thermostat should be a 195. You should stick with this if no modifications have been done (LARGER RADIATOR, ELECTRIC FANS, ETC.) A lower temp thermostat is only benifical if you have done these modifications or you are trying to get the vehicle to run in closed loop (richer for more power, vehicle thinks it is cold so it fattens up the fuel curve and runs rich). The drawback to a lower operating temp thermostat is faster coolant flow through the radiator. This can be a huge problem if you are using the vehicle in low speed applications, no or slow air flow across the radiator can case an overheating condition. A higher temp thermostat can regulate the coolant and temp better. Ideal operation temp should be 200-220. Hope this helps, Shad

azgoldeagle:

 JD,  Are you changing the thermostat for a reason? Is yours failing or sticking? Your factory thermostat should be a 195. You should stick with this if no modifications have been done (LARGER RADIATOR, ELECTRIC FANS, ETC.) A lower temp thermostat is only benifical if you have done these modifications or you are trying to get the vehicle to run in closed loop (richer for more power, vehicle thinks it is cold so it fattens up the fuel curve and runs rich). The drawback to a lower operating temp thermostat is faster coolant flow through the radiator. This can be a huge problem if you are using the vehicle in low speed applications, no or slow air flow across the radiator can case an overheating condition. A higher temp thermostat can regulate the coolant and temp better. Ideal operation temp should be 200-220. Hope this helps, Shad

 Thanks Shad - I'll verify that Ruby is running a 195 and I'll stick with that since I haven't done any modifications to her. I appreciate the quick reply.

JD

 JD, I understand that you had some overheating issues when you were doing the Woodpecker trail. That day keep in mind that we had a heat advisory and the slower you crawl and drive on these trails, the less air flow across the radiator for cooling. Also keep in mind that if you had the AC on the condensor gets even hotter due to this and the high pressure side of the AC system is off the charts. This condition can kill a compressor in a heart beat. Also a automatic trans builds heat as well. The cooler for the auto trans in in the radiator also. This puts alot of strain on the coolant, atf, and the radiator. Alot of guys are using a add on Electric fan (like a Black Max) between the stock fan and the radiator inside the shroud. This allows for the slow speed crawling but keeps the airflow constant no matter what the rpm is of the engine. A switched system is good for this so you can turn it off for water crossings. If you have low miles and this is the only time you have had a heating issue leave well enough alone. Don't change that thermostat just yet. Change the coolant and run a water suppliment like water wetter or napa cool. If the therm was bad it would be stuck open and the Jeep would run cool all the time(except slow speed crawl) or it would be stuck shut and you would overheat all the time. Shad

azgoldeagle:

 JD, I understand that you had some overheating issues when you were doing the Woodpecker trail. That day keep in mind that we had a heat advisory and the slower you crawl and drive on these trails, the less air flow across the radiator for cooling. Also keep in mind that if you had the AC on the condensor gets even hotter due to this and the high pressure side of the AC system is off the charts. This condition can kill a compressor in a heart beat. Also a automatic trans builds heat as well. The cooler for the auto trans in in the radiator also. This puts alot of strain on the coolant, atf, and the radiator. Alot of guys are using a add on Electric fan (like a Black Max) between the stock fan and the radiator inside the shroud. This allows for the slow speed crawling but keeps the airflow constant no matter what the rpm is of the engine. A switched system is good for this so you can turn it off for water crossings. If you have low miles and this is the only time you have had a heating issue leave well enough alone. Don't change that thermostat just yet. Change the coolant and run a water suppliment like water wetter or napa cool. If the therm was bad it would be stuck open and the Jeep would run cool all the time(except slow speed crawl) or it would be stuck shut and you would overheat all the time. Shad

 Shad - I haven't had an issue with it since I left the trail. It only overheated when doing some of the more challenging obstacles and we were running slow. It would run up to 260 degrees and when I put on the heater it would drop down instantly back to 210 - 215 degrees. It never overheated while sitting stationary.  And "YES" we were running the AC on 3/4's speed the whole time we were wheeling as it was fairly hot last Saturday and I had 4 riders in Ruby who wanted to stay cool. I will try your suggestion of changing the coolant and run a water supplement. In all the times out wheeling this is the only time that I've had an issue with an overheating problem.

Do you think that I should swap out my tranny fluid and transfer case fluid as well?

JD