hansen65

I have been having overheating issues and have changed the following:

Thermostat
Radiator Cap
Coolant flush
Water Pump
Electric Fan Motor
Resistor for low / high speed circuit (on fan shroud)
Flushed the radiator and AC condenser fins with the fan shroud off with water to clean all dirt and debris

Since changing these items I went from overheating all the time to now just when climbing a hill with the AC on at highway speeds. If I slow way down to about 45 the temp wont climb past about 3/4 on the gauge but if I don't kill the AC or slow down it will eventually overheat and boil over.

I do not have trouble around town or on trails. The issue only occurs climbing hills at highway speeds like the road to Big Bear or going up the 5 fwy to Gorman and it's only when the AC is on. Outside temps don't seem to matter, last time I was running hot (3/4 temp gauge) it was only 85 out.

The jeep has a magnuson supercharger with inter cooler but that has been the same for several years. This problem just started this summer. I am running 37 inch tires with 5.13 gears (just changed from 35" tires). Also just upgraded to a PSC ram steer assist. In doing so I went to a larger pulley on super charger (less boost) which should reduce engine temperatures. I also changed my plate style trans cooler out for a tube and fin to help get more air flow through the radiator.

Any suggestions would be greatly appreciated.

ronjenx

Does the temp gauge climb past vertical when sitting with the engine idling?

Did you clean the radiator fins because there was mud in them? If so, you may have mud between the radiator and the A/C condenser. The only way to get it clean is to remove one of them.

Do you have anything in front of the grill that would disturb the airflow into the grill?

Anything that would increase the pressure in the engine bay will degrade cooling at highway speed.
Examples: removal of the air dam without replacing with a similarly shaped skid; removal of inner fender liners; hood with vents near the windshield. Probably no single item will cause issues, but several may add up to inadequate cooling.

Another thing to consider is the temperature of the air charge. Make a list of things that may be different from years past that would affect airflow through the inter-cooler fins.

Could be the addition of the bigger tires brought the cooling load past the system's capability to get rid of heat if you have any of the items above.

Riflejk

Funny had the same thing happen to my 07 after PSC was installed. Overheating with any grade in Colorado. Only thing that cured it was a new aluminum rad. No supercharger.

hansen65

I had pulled the radiator out completely and washed the fins of the condenser and radiator. There was some bugs and dust from the desert but this thing has never seen mud beyond a small puddle on a trail.

I have a winch mounted on a Poison Spyder BFH bumper. This has been the same for about a year with no issue last summer.

I have had the poison spyder hood louver kit since I installed the super charger 3.5 years ago. The inner fenders have have been trimmed to clear my poison spyder front fenders but they are in and more or less covering the same area. I do not have an air dam or skid. The crash bar was removed when the BFH was installed.

I did switch from a flat K&N filter in the stock box with several holes cut into it for better air flow to a conical K&N filter. There is a heat shield around the K&N so I would think that intake air temp should be about the same but I have no way to verify that.

hansen65

I thought about doing an aftermarket radiator but was worried I would just mask some other problem. Which company did you go with? Most don't have internal automatic transmission coolers but the ones that come an external one mount where my inter cooler is for the super charger.

What about upgraded fan, has anyone found a reliable upgrade to the stock fan? I did some research and some people were talking about going to a Spal fan but also read that several people had problems with those blowing fuses and wearing out also. I have been considering an LS upgrade and heard that they use the penstar fan which pulls 4000 CFM but they are variable speed driven by the computer not like the old 3.8L fans that just get a dumb high low signal.

hansen65

Here is a recent picture of the front of my JK

Mark Doiron

If you have an Android device, the app Torque Pro and an inexpensive OBD/Bluetooth adapter will let you monitor various temps, including ambient, coolant, and intake.

zstairlessone

The intercooler for your SC covers a lot of real estate in front of your radiator cutting air flow through the rad and putting hotter air through. I know you said it's been on for a long time, you might look for a relocation kit for the cooler - or make one - possibly with its own fan to draw air through it so it still works just not in front of the radiator. Other than that you will probably need to go with a high performance replacement radiator.

Riflejk

Can try a different fan no personal experience their. However I've seen RV misters work well. Just mist as needed.

hansen65

Thanks for the tips guys. I happen to have an odbII Bluetooth scanner I didn't think to try it earlier. I will see what the inlet air temps are looking like. Any idea what normal would be on a super charged engine???