Hot when running A/C

[cwkerr007]

This has been a problem with this jeep since we owned it. If it is above 90 and you run the ac it stays around 200 and too much stop and go and it will overheat but it runs all day without issue with no ac. Let me go ahead and say it had orig rad in it and had it rodded out and flushed the block put new cap (3 diff ones) running 160 therm and I have changed water pump. Now I'm fixing to do what ya'll say don't do, I'm putting a higher capacity fan blade cause i can put my house fan in front of rad and let it idle in the sun all day never gets over 190 ! So if you have a better solution I'm game cause if this fan doesn't do it I've had enough of this gutless paperweight of a motor and have a dakota bellhousing and a built 318 just beggin to play. But thats a lot of work I just want to use my ac in my daily driver that i haven't done for 2yrs now! 97 sahara 4.0 manul trans no mods completely oem even tires and wheels .

 

[L J]

This has been a problem with this jeep since we owned it. If it is above 90 and you run the ac it stays around 200 and too much stop and go and it will overheat but it runs all day without issue with no ac. Let me go ahead and say it had orig rad in it and had it rodded out and flushed the block put new cap (3 diff ones) running 160 therm and I have changed water pump. Now I'm fixing to do what ya'll say don't do, I'm putting a higher capacity fan blade cause i can put my house fan in front of rad and let it idle in the sun all day never gets over 190 ! So if you have a better solution I'm game cause if this fan doesn't do it I've had enough of this gutless paperweight of a motor and have a dakota bellhousing and a built 318 just beggin to play. But thats a lot of work I just want to use my ac in my daily driver that i haven't done for 2yrs now! 97 sahara 4.0 manul trans no mods completely oem even tires and wheels .

a couple of points:

the engine is designed to run at 210⁰ when at operating temp
the 160⁰ thermostat does nothing to lower the operating temp

 

[freedom_in_4low]

This has been a problem with this jeep since we owned it. If it is above 90 and you run the ac it stays around 200 and too much stop and go and it will overheat but it runs all day without issue with no ac. Let me go ahead and say it had orig rad in it and had it rodded out and flushed the block put new cap (3 diff ones) running 160 therm and I have changed water pump. Now I'm fixing to do what ya'll say don't do, I'm putting a higher capacity fan blade cause i can put my house fan in front of rad and let it idle in the sun all day never gets over 190 ! So if you have a better solution I'm game cause if this fan doesn't do it I've had enough of this gutless paperweight of a motor and have a dakota bellhousing and a built 318 just beggin to play. But thats a lot of work I just want to use my ac in my daily driver that i haven't done for 2yrs now! 97 sahara 4.0 manul trans no mods completely oem even tires and wheels .

Define "overheat".

 

[mjonesjr84]

Mine will get up to 225*F when the AC is running. This is perfectly normal.

 

[5TTTj]

Replace the thermostat with a 195 before trying anything else. Im in south Florida and run stock everything, my temp runs 210 all day long with or without the AC on, day or night. IMO you cannot go wrong with stock everything. Are you currently using fan clutch and do you still have the fan shroud ?

 

[cwkerr007]

350 chevya couple of points:

the engine is designed to run at 210⁰ when at operating temp
the 160⁰ thermostat does nothing to lower the operating temp

This engine was designed in the in the 60's it was in production from 64-06 no it was not designed to run 200+ and if the cooling system is working properly the motor should run below the normal operating temp and with this motor it was originally 180 and the reason they sell 160 thermostats is to adjust your driving temp so yes it does change your operating temp if the motor is being cooled by the system cause any system that is operating properly and you remove the stat it should drop below 160 if it doesn't then you have an insufficient cooling system. You take any 318 dodge or 350 chev or 302 ford and take out the stat on a 50deg day and it has a 3core rad then it will never see 180 if its a 318 with solid fan close to rad you will never get it to idle it will run so cool i guess everyone has grown used to excepting the auto industry standard of lets just get it to cool just enough to get the job done but that wasn't the idea when this motor design was born . It was overcool and let the stat do the work . Well when the stats were made for that .

 

[cwkerr007]

Replace the thermostat with a 195 before trying anything else. Im in south Florida and run stock everything, my temp runs 210 all day long with or without the AC on, day or night. IMO you cannot go wrong with stock everything. Are you currently using fan clutch and do you still have the fan shroud ?

Yes it is all stock i am currently going old school with it and putting a 6blade fkex fan on it . That was fun finding a reverse rotation fan blade . I was going to use the explorer fan on the jeep clutch but i would have to get the right thermal clutch to go with it so i just went solid and i don't mind the noise as long as i can put my hand on the motor when operating. Hell my truck is a 5.9 dakota with 3 in straights out the back lol. Thanks for the help though i'll post a after post in as soon as i get the fan on

 

[cwkerr007]

Replace the thermostat with a 195 before trying anything else. Im in south Florida and run stock everything, my temp runs 210 all day long with or without the AC on, day or night. IMO you cannot go wrong with stock everything. Are you currently using fan clutch and do you still have the fan shroud ?

Replace the thermostat with a 195 before trying anything else. Im in south Florida and run stock everything, my temp runs 210 all day long with or without the AC on, day or night. IMO you cannot go wrong with stock everything. Are you currently using fan clutch and do you still have the fan shroud ?

yeah i vacationed in sarasota one summer I feel your pain I live in gods toilet beaumont tx and it's all humidity hot but this jeep will not get above that 180 it don't care if you run it hard and idle in the sun it never looses coolant and never gets above 180 BUT turn that ac on and if the sun is out and you get in stop and go traffic you'll be in trouble but as long as your cruising freeway it's fine and yes i watched the guy rod out the rad and i flushed the block till the water was clear and changed the water pump cause thats when i changed the stat cause after all that it had 195 in it and i put the 180 in it and it dropped the temp down so i thought i had it but soon as i turn on ac those thoughts of joy went away as the gauge got past 200 and i'd rather be hot than the jeep but i'm hoping it's an airflow proplem. I even sealed the shroud and cores with seals so to get max flow.

 

[Unique Username]

Weird. Don't run a 160 thermostat. The system is designed for 195 and if you run a 160 thermostat the fuel system will add more fuel to the mix trying to get temps to 195. The design is to run at 195+. You are fighting the system to run 160.
If you want more cooling, you run the 2791 clutch. You won't find the 7 blade fan, so run it on the OEM fan you have.
Gauge temp "if accurate" will run 210. Mine runs at 210 when it's 118° in Phoenix.
Explorer fan has been proven to not work, don't waste your money.
Make sure you have the correct radiator, cap, water pump and thermostat with the correct fan and clutch. It won't overheat.

 

[cwkerr007]

Weird. Don't run a 160 thermostat. The system is designed for 195 and if you run a 160 thermostat the fuel system will add more fuel to the mix trying to get temps to 195. The design is to run at 195+. You are fighting the system to run 160.
If you want more cooling, you run the 2791 clutch. You won't find the 7 blade fan, so run it on the OEM fan you have.
Gauge temp "if accurate" will run 210. Mine runs at 210 when it's 118° in Phoenix.
Explorer fan has been proven to not work, don't waste your money.
Make sure you have the correct radiator, cap, water pump and thermostat with the correct fan and clutch. It won't overheat.

I'm going solid fan and eliminate the clutch and as far as the fuel inj goes if it is dumping more fuel thats fine that will help it run cooler but it gets fuel consumption from the temp sens then every time it gets hot with the ac on it leans out and the stat has nothing to do with it but this motor was designed to run 180 with keaded gas and a carb but the ecm is unaware of that and the fi system is the one struggling to keep up with the drastic changes in temp and i am determined to get this thing down to the 195 that the system is supposed to compromise too. Now lets not everybody forget my orig post it only gets hot with ac in ext temps at low rpm but it's july now and you can't make that gauge move after it's operating UNLESS ac comes in the pic but i just got my new fan blade and i'm going to flush again and put a more significant overflow and post the results thanks everyone i love this forum everyone is great thanks see ya in a few days. Oh i forgot i have tried new caos(3)and even took one off my other trucks no change and it never looses coolant.

 

[cwkerr007]

And it has a copper rad oem and it's manual no cooler. I am a believer in oem design I bought this sahara after searching forever to find orig i found this one and took the wheels off and put the oem wheels and tires back on it so all parts were oem when we got it and as soon as it got summer is when this was found out and have replaced everything with oem and still problem that is why i have resorted to aftermarket parts and old school tech I'll let ya'll know

 

[Jayramble]

Had same issue, with an automatic I installed the Derale 20561 transmission cooler that is bolted underneath the drivers side attached to the frame. This freed up the airflow through the radiator and ac condenser, I did also install a 12 inch push fan with a manual switchI engage during the hotter days here in Dubai. Engine runs cooler now with the gauge indicator stays around middle.