hey guys i need some help. i have an 01' supercrew with a magnuson supercharger on my triton 5.4 turning about 4-5 lbs of boost. heres the problem... my truck is overheating at idle on really hot days and when im riding around town. as long as im on the road doing over 40 or 50 i never have this problem. i installed a high performance radiator and heat exchanger (lighting upgrades from lightning force performance) at the end of last summer and im still having problems. last week i put a 160 degree thermostat and i think its makin things worse. i just got off the phone with a guy from magnuson and he thinks i need to get my engine dynoed and retuned cuz he thinks i may be running too lean.. im hoping some of you experienced guys can kinda point me in the right direction. id hate to burn this thing up or blow a head gasket. i really need to cool this puppy down. i want this thing to idle all damn day with the ac on high and not have any trouble with overheating. help me out please. thanks

 

My thoughts would be to look at the cooling fan. I assume it is a viscous fan? With the engine cold and turning the fan by hand there should be a drag.

 

its an electric fan. and it turns very easy by hand when the engine is off. its wired directly to my ignition, because a few summers ago i was having trouble with the thermostat on the fan so i had it wired directly to my ignition. when my ignition is on the fan is on. and iv been told its a very efficient fan. i just dont know any of the specs on it or what brand it is

 

It still sounds like you have insufficent air flow through the rad at idle.
However it might be worth getting the ignition timing checked.

 

If it's only overheating at idle, I doubt it your tune. You might want to check your settings on your fan to see when (and if) it's coming on. How many fans and what size are they. Do you have air conditioning? Is your fan set up such that when the compressor is running the fan is running?

 

Where is your intercooler and what size is it?
Do you even have an intercooler?
Has it always ran hot?
If not what have you done prior to it running hot?