Us XJ owners in the southwest (who wheel in the Mojave Desert) use 180 thermostats due to the extremely high heat. When it's 110+ outside, it makes a huge difference and helps keeps the engine temp ~200 on the trails. Hood louvers + high-performance water pumps + 60/40 water to antifreeze + 180 thermostats = no issues in super high heat.
A lower temp thermostat does nothing to improve cooling in high heat weather (or fix overheating). The thermostat only sets the temperature floor. The efficiency of the radiator, fans, water pump and fluid to dissipate heat set the ceiling. The tempurature rating on the thermostat is only when it OPENS the fluid to the cooling system (it's job is to stay closed until the engine reaches operating tempurature, (195 for the 4.0), it does not improve cooling efficiency (magically make your cooling system run cooler). It is only a door, if your cooling system can not maintain 210, then it doesn't matter if the door opens at 180 or 195 (especially in hot weather). I have wheeled Mojave, Death Valley, Ocitillo Wells, Big Bear, Calico and Johnson Valley numerous times, all with a stock XJ cooling system with a 195 thermostat (only added hood louvers). Because I know what the thermostats actual function is.
Very helpful, mine is running around 180 and it’s must be from previous owner putting in a 160 thermostat. I was doubting myself but went with my gut to buy a 195 yesterday. Still doubted myself but found your video! I’m feel much better now knowing I’m making the right correction. Thank you!
GREAT TUT!!!........have a 94 sport and im always stumbling around for good to the point vids this was perfect, i didnt fall into a single rabbit hole!!!
Great video, about to do a tstat swap on my xj and you just answered the 2 questions I had with this video. Thanks again and subscribed to your channel for future help.
Thanks for posting. I have a 1980 Cj7 and the temp gauge stays on the high side slightly below H. The engine runs great my thermal reading on the housing and heater hose is around 205. I was just about to change thermostat with 180deg and now that I saw your video perhaps I should not do anything.
I'm not very familiar with CJs, but I'd assume they have a very basic cooling system pretty much identical to XJs. If it's running a little hot, I would think maybe the fan clutch (if it has one) or the radiator is slightly clogged perhaps
I live in good ol Portland2.0 California and 98.99% of the time im stuck in traffic because no one knows how to drive here it gets a little hot in the summer months i Run a 195 high flow thermostat in a 2 core CFS and it’s been 210 regardless of 100° temps or not with the ac on I ran a 180 and she ran like crap so I went back to 195
Whoop! I’ve had such terrible luck with failsafe. They don’t seem to be optimal for the 4.0, where the 4.0 can easily operate at 230° on a warm day, which is 35° over the opening temp. My failsafe t stat would fail within a few months. And that happened over a few years. Picked up almost 2mpg on the highway when the jeep was at proper temp. Mopar for the win
Will the thermostat listed work for a 1996 XJ with the 4.0L? I looked at thermostats on rock auto for the 96 model and it doesn’t show that specific Mopar thermostat as an option.
A failed closed thermostat is easy to diagnose. Once up to temp the thermostat should open at, check the upper radiator hose. If it does not get warm or hot to the touch, the thermostat is stuck closed (no fluid flowing through the radiator). An another dead give away is if the engine overheats while just idling as the fluid just keeps recirculating through the motor constantly increasing heat. The other possible cause for the above symptoms would be a failed water pump.
I’m using the Felpro gasket (the one with the red stuff lining the face of the gasket). I wasn’t sure about the thermostat itself, so I used a little bit of RTV on the thermostat though. As expected, the thermostat fell out of its position on my first attempt and instead of playing games and breaking it or the housing, I used just enough of the RTV as stated previously, and now I’m putting everything back together as we speak.
No, something is leaking somewhere. If you're losing coolant, it's either leaking through a hose/ seal/ heater core, or burning through the piston rings in the combustion chamber.
Us XJ owners in the southwest (who wheel in the Mojave Desert) use 180 thermostats due to the extremely high heat. When it's 110+ outside, it makes a huge difference and helps keeps the engine temp ~200 on the trails. Hood louvers + high-performance water pumps + 60/40 water to antifreeze + 180 thermostats = no issues in super high heat.
A lower temp thermostat does nothing to improve cooling in high heat weather (or fix overheating). The thermostat only sets the temperature floor. The efficiency of the radiator, fans, water pump and fluid to dissipate heat set the ceiling. The tempurature rating on the thermostat is only when it OPENS the fluid to the cooling system (it's job is to stay closed until the engine reaches operating tempurature, (195 for the 4.0), it does not improve cooling efficiency (magically make your cooling system run cooler). It is only a door, if your cooling system can not maintain 210, then it doesn't matter if the door opens at 180 or 195 (especially in hot weather). I have wheeled Mojave, Death Valley, Ocitillo Wells, Big Bear, Calico and Johnson Valley numerous times, all with a stock XJ cooling system with a 195 thermostat (only added hood louvers). Because I know what the thermostats actual function is.
Very helpful, mine is running around 180 and it’s must be from previous owner putting in a 160 thermostat. I was doubting myself but went with my gut to buy a 195 yesterday. Still doubted myself but found your video! I’m feel much better now knowing I’m making the right correction. Thank you!
Just installed new 195 thermostat and now my engine is running around 205! Very happy
@@Luke-ig7libetter on emissions, better heat, better mpg!
My favorite tutorial. I just swapped out my thermostat, the sensor, and the housing with your help!
GREAT TUT!!!........have a 94 sport and im always stumbling around for good to the point vids this was perfect, i didnt fall into a single rabbit hole!!!
Such a great tutorial, probably the best I’ve seen, answered all the questions one may have.
I know you watched the one where the dudes head was fully In the way too. So many bad videos for this particular issue. Lol
Loved the humour in this thanks for the help!
Has anyone else noticed how the block's port for the heater coolant is way smaller than the thermostat housing port?
Great video, about to do a tstat swap on my xj and you just answered the 2 questions I had with this video. Thanks again and subscribed to your channel for future help.
Informative and hilarious all in one.
Good Stuff!
Oh my god this video is great. "aaaaaand now you're ready to do an engine swap." haha!
Thanks for posting. I have a 1980 Cj7 and the temp gauge stays on the high side slightly below H. The engine runs great my thermal reading on the housing and heater hose is around 205. I was just about to change thermostat with 180deg and now that I saw your video perhaps I should not do anything.
I'm not very familiar with CJs, but I'd assume they have a very basic cooling system pretty much identical to XJs. If it's running a little hot, I would think maybe the fan clutch (if it has one) or the radiator is slightly clogged perhaps
I live in good ol Portland2.0 California and 98.99% of the time im stuck in traffic because no one knows how to drive here it gets a little hot in the summer months i Run a 195 high flow thermostat in a 2 core CFS and it’s been 210 regardless of 100° temps or not with the ac on I ran a 180 and she ran like crap so I went back to 195
Whoop!
I’ve had such terrible luck with failsafe. They don’t seem to be optimal for the 4.0, where the 4.0 can easily operate at 230° on a warm day, which is 35° over the opening temp. My failsafe t stat would fail within a few months. And that happened over a few years. Picked up almost 2mpg on the highway when the jeep was at proper temp. Mopar for the win
When my buddies xj thermostat failed. It wasn’t stuck in the open position but the closed. So his engine literally blew up. He got unlucky.
Great video and instruction.
Can anybody tell me why I can’t seem to find the one with that little needle valve for a 1998? Does it matter can I just use this one?
Will the thermostat listed work for a 1996 XJ with the 4.0L? I looked at thermostats on rock auto for the 96 model and it doesn’t show that specific Mopar thermostat as an option.
I'm certain all of the thermostats are the same for every year of the 4.0L, yes
@@WAEMIDIV Thank you!
Great vid. Thanks.
My 92 Limited has the threaded sensor port.
yes I believe they added that sensor in 91. At the time of making the video I'd never even seen a 91-95 before
The reveal of the dropped Jeep at the end 😂
Mine failed in the closed position! It was a very frustrating experience trying to figure out what was going on!
I'm hoping that's the issue on my Comanche. I think it's over heating
@@vhssociety it’s worth checking!
A failed closed thermostat is easy to diagnose. Once up to temp the thermostat should open at, check the upper radiator hose. If it does not get warm or hot to the touch, the thermostat is stuck closed (no fluid flowing through the radiator). An another dead give away is if the engine overheats while just idling as the fluid just keeps recirculating through the motor constantly increasing heat. The other possible cause for the above symptoms would be a failed water pump.
What about bleeding air???
That I covered in the radiator video, linked in the description
GREAT VIDEO!! I just changed mine with your helpful video. LMAO the ex wife joke buahahahahahaahahah
So do I need a paper gasket?
I’m using the Felpro gasket (the one with the red stuff lining the face of the gasket). I wasn’t sure about the thermostat itself, so I used a little bit of RTV on the thermostat though. As expected, the thermostat fell out of its position on my first attempt and instead of playing games and breaking it or the housing, I used just enough of the RTV as stated previously, and now I’m putting everything back together as we speak.
"Engine Swap" ?
Forget about it!
Will thermostats being bad cause coolant loss?
No, something is leaking somewhere. If you're losing coolant, it's either leaking through a hose/ seal/ heater core, or burning through the piston rings in the combustion chamber.
I think my seal was shot. It was definitely leaking out of the thermostat housing and when I took it off the seal was pretty rough looking.
Hahaha engine swap😂
also a wisco jeep nerd! XD