3.6 cooling

[Grahame]

Originally Posted by YamahaDOC

I was sure there is a tuner that can adjust the thermo fan temp cut in? That would be the best solution I think?

I've not heard of one that allows you to vary the temp but a Bully Dog Tuner gives you manual control of the thermo fan.

[ymy-88u]

easter trip i done from canberra to fraser island towing a off road camper, engine and trans were getting to 120 degrees,
I'm going back this new years but no trailer this time as these little cars aren't heavy duty enough for that on the sand they got no balls and spend most of the time near the limiter

[wjlimited]

Originally Posted by ymy-88u

easter trip i done from canberra to fraser island towing a off road camper, engine and trans were getting to 120 degrees,
I'm going back this new years but no trailer this time as these little cars aren't heavy duty enough for that on the sand they got no balls and spend most of the time near the limiter

Totally agree with you, after all of these comments I thought maybe my 13 Rubicon was a one off. It use to be unusable towing my camper in soft sand, and sat between 100-110c at highway speeds on the flat.

One trip I ditched the trailer and put two swags and some other stuff on the roof and the car barely got out of 3Rd gear because of the drag, that trip to Fraser is what made me go back to a Grand Cherokee.

[blownjk]

Believe it or not, these things have a 101degC thermostat for emissions.
Normal temps are 100-106 and controlled by the ECU/fan....so pretty hot..
My 14 JK is supercharged so fitted a 170f thermostat and with fan settings adjusted in the tune, it runs at 85-87C all day now. Fan starts at 88C. Never goes above 92C even at Fraser. (No trailer admittedly.....But S/C does makes easy work of the sand!...or hills!...or whatever!)
Radiator seems to have plenty of capacity, just the thermo and fans are set fairly hot.
Engine really appreciates it, performs better and under bonnet is cooler.
PITA that the ECU controls the fan so needs a tuner to adjust.

[YamahaDOC]

Originally Posted by blownjk

Believe it or not, these things have a 101degC thermostat for emissions.
Normal temps are 100-106 and controlled by the ECU/fan....so pretty hot..
My 14 JK is supercharged so fitted a 170f thermostat and with fan settings adjusted in the tune, it runs at 85-87C all day now. Fan starts at 88C. Never goes above 92C even at Fraser. (No trailer admittedly.....But S/C does makes easy work of the sand!...or hills!...or whatever!)
Radiator seems to have plenty of capacity, just the thermo and fans are set fairly hot.
Engine really appreciates it, performs better and under bonnet is cooler.
PITA that the ECU controls the fan so needs a tuner to adjust.

Awesome! Do you have a superchips?

[blownjk]

Originally Posted by YamahaDOC

Awesome! Do you have a superchips?

HP Tuners

[Banshee]

Originally Posted by blownjk

Believe it or not, these things have a 101degC thermostat for emissions.
Normal temps are 100-106 and controlled by the ECU/fan....so pretty hot..

Not sure about the actual efficiency curve, but in theory the hotter the engine is, the more efficient it is. This is because all the heat you remove with the radiator is waste that could have been used to further expand the gas in the cylinder or spin the turbo etc.

In practice, of course, if you tried to insulate it completely & not cool it, the materials it is made from would not cope with the temperature. But if they could, radiators & cooling systems would not exist and fuel efficiency would be higher as more energy was harvested from the combustion. Also you have the problem of the inlet heating the fuel air mix, reducing the amount that gets into the cylinder, and that reduces power.

In comparison, my bike will sit at a minimum of 80C and the fan won't kick in until 106C. Highest I have seen was in summer while stopped in traffic & that was 114C.