just bought truck 2 weeks ago but mods as far as I know are Nitto Terra Grappler all terrains 285 75 16 on the stock rims 4.7 crew cab, hard tonneau cover, superchips tow tune, stock transmission cooler bypass an aftermarket one installed in front of radiator, radiator replaced one and a half years ago and I just did a 180 degree thermostat, water pump, coolant flush 70/30.

after 150 miles of steady cruisin on flat ground in south Florida down the highway anywhere from 65 -75 miles an hour temperature gauge struggle to stay at the halfway point and has gone as far as 3/4 of the way up temperature gauge. outside temp was 84 at start and now 94. Tried some drafting.

 

OK, so you're going to remove the c ooling fan and hope that makes it run cooler?

 

No 99% of the people who remove them say it runs the same temp. Even seen paoeple say they never hear the electric replacement come on.

Did it because i am on a 1900 mile round trip and supposed mpg gain. Ofcourse I brought the fan in tools necessary to reinstall. I'll see how the mountain part of my trip goes tomorrow.

 

Double post

 

I don't think the fan is an issue at 65-75 mph. You've got other issues.

 

Well the energy required to turn the fan sure does eat some power. I took mine off my 2001 Durango 4.7L and it sure helped it rev up a lot easier. The only time my electric fan came on was if I was sitting in traffic for an extended period of time, or with my A/C as it was designed to do. Not once did I ever have it go outside the normal operating temperature range, even in the 103 degree summers of Nebraska.

 

100% positive the whole cooling system is newmaybe it's a combination of the 3.55 gear ratio in the bigger tires lugging the motor too much. 80 miles an hour at 2000 rpm.

truck is running great so far not burning any coolant or oil

 

Thats a good possibility. Maybe you can hookup to the obd and read out the load %. I have a scangauge II that I use.

I had one I worked on years ago, running hot at highway speed. Fine at stops, after testing and checking things for 2 days I finally noticed someone had put the fan on backwards.

 

My 2014 Hemi 4x4 with 3.92s cranks 2kRPM at 80. I believe my Durango would run about 75 or so at 2kRPM with 3.55s and 31 or 32" tires.

 

Last 30 mins of trip today was mountain highway at 45mph with windows down and a/c off to enjoy the air. Was still 85 deg. Coolant quickly dropped to below half on gauge and stayed there even when stopped at traffic lights. Occasionally going too the half way mark(where the stock thermostat was).

As of now i am going to leave the whole cooling system stock.