Novak Conversions Jeep Wrangler TJ radiator

Overheating and leaking when A/C is on

I bought a fan clutch but realized i Have an electric fan when I started taking it apart . I ran it last night with the flush in there and it overheated without the ac on. Took it about 8 miles. It was at a constant 210 and then straight to overheated. Had to tow it back home.

If it were me... I would restore the cooling system back to stock, as the electric fan is not cutting it, for whatever reason. I've never been fond of after-market electric fan systems.

Also, when replacing the thermostat, make sure it has the air-bleed hole in it. If it doesn't have that, air can accumulate under the thermostat in the closed position, and since air is a poor conductor of heat, the thermostat may not respond quickly enough. And if your electric fan thermostat sensor is wired into your thermostat housing, it's not going to sense heat quickly enough either.
 
Did you find the problem? I’ve had very similar issues the last two times I’ve driven my TJ.

I bought a fan clutch but realized i Have an electric fan when I started taking it apart . I ran it last night with the flush in there and it overheated without the ac on. Took it about 8 miles. It was at a constant 210 and then straight to overheated. Had to tow it back home.
 
Hello ,
I am new to the site even though I look at the discussions quite often.
I need help on what to do with my 1999 Jeep Wrangler Sahara 6 cyl.
I have had the jeep 8 years with only a radiator and thermostat replacement when I first bought it.
I have not had any problems with the jeep what so ever except for my airbag light came on and just never fixed it.

I was driving to work with the a/c on( I did notice it wasn't as cold as it usually gets) and the check gauges light came on and I immediately pulled over for all my coolant to spill on the ground. I let it cool off and put coolant back in it to drive it home 45 mins without a/c on and it did fine.

I noticed it had a leak in the radiator and so ordered all parts to replace coolant system.

I didn't know to buy all mopar parts so this is what I replaced.

Motorad 195 Thermostat with weep hole

DAYCO wATER PUMP

Thermostat housing

liland Global oe quality all aluminum radiator.

After replacing all of this and adding new coolant, It did the exact same thing. Overheated and coolant spilled everywhere just like before( only when a/c is on).
I did not burp the system and I did not flush the system as it looked very clean( but maybe hind sight I should have)

Oil is clean, no coolant there.

Can someone help redirect me before I loose my mind.

Since you didn’t burp the system, you may have had the jiggler stay shut on you which would have prevented the thermostat from opening until it was insanely hot and mixed in with air pockets. Or, simply not burping it at all sent you on a path for an air pocket to cause doom.

In my experience, a thermostat should be replaced once it overheats because it can stay stuck closed on you. Another TS did just that after overheating due to my water pump failing causing things to go nuclear (it was purple iridescent colored and stuck closed during the boil test).

I once replaced fluid and a Mopar/motorad thermostat, but I didn’t cut out the jiggler or simply drill a new hole. This resulted in the jiggler sticking and the radiator turning into old faithful while at working to remove air from the system. I contacted Blaine immediately and he helped explain exactly what happened.

I’ve also had a new Motorad thermostat be stuck closed during the boil test, so I knew not to install it (crisis averted).
 
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Are you doing the work yourself or are you paying a mechanic to do the work? If you are paying a mechanic, you might want to find a better mechanic. It makes no sense that you paid all this money, and you know the issue is that your car is overheating when the AC is on, and a mechanic cannot diagnose what the problem is except charging you all this money, over and over again. If the electric fan is faulty, a good mechanic should be able to diagnose this issue. I can sit in park with my AC on, and my Jeep won't overheat. Of course, I don't live in the desert. A mechanic should be able to let the car run in park, turn on the AC, and make sure the fan is coming on, and diagnose any issues.

Also, it is not a good idea to let your Jeep continue to overheat and blow out radiators. You could fry your engine. I would NOT run the AC until the issue is properly repaired. Although now, it seems the issue must be resolved because it is even overheating without the AC on. I really hope that you are working on this Jeep yourself and not paying a mechanic to do it.

Lastly, you might want to run your Vin information to see what your Jeep came with from the factory. There are certain part upgrades that were added if the Jeep came from the factory with AC. If the Jeep didn't come from the factory with AC, then this might explain all the "mickey mouse" parts added to your Jeep like the electric fan. I believe one such part was a heavy duty alternator. It seems the PO knew there was an issue and they tried to solve it with an electric fan, instead of finding out what the real issue was. I think your issue is an inadequate radiator, clogged coolant system, and maybe a faulty compressor clutch. Maybe all the original pulleys aren't there either since the original fan was removed. I would also get rid of the "mickey mouse" electric fan setup, and return it to stock. This shouldn't be a rocket science issue for a good mechanic. I've had issues with my AC, and my mechanic was able to fix it pronto. Luckily, I am the Original Owner so no one Mickey Moused my Jeep. Good Luck.
 
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I think it may be fixed now. Have not had a chance to drive it a long ways yet (only 30 mins) I bought another thermostat and replaced the temperature sensor and burped it like crazy- elevated and with heat on full blast. The A/c still isn't cold but that's probably just coincidental thing maybe.
 
I think it may be fixed now. Have not had a chance to drive it a long ways yet (only 30 mins) I bought another thermostat and replaced the temperature sensor and burped it like crazy- elevated and with heat on full blast. The A/c still isn't cold but that's probably just coincidental thing maybe.

You probably need to recharge the AC system, unless it was cold and now it isn't. Then, you probably have a leak. There is a proper way to recharge the system and it is important that it is done right or you could ruin it. My understanding is that it needs to be evacuated, so that it has a vacuum, then there is oil for the system, and the refrigerant. Mine had a leak for awhile, and didn’t get real cold until my mechanic found the leak. Now, it is cold all the time.
 
Novak Conversions Jeep Wrangler TJ radiator