son has a 2004 ram 4.7 that is having overheating issues. the gauge is reading about 1/2 way between normal and redline. installed new thermostat yesterday. the clutch fan seems to have no excessive play in it and the electric fan is working. took temperature readings of upper and lower hoses and read within about 10 degrees of each other.(145-155) temperature readings of radiator show randomly at 105-120 degrees. one area about 3"x 3" was reading at 170 plus. any help is greatly appreciated.

 

Sounds Normal, Mine runs at middle of temp gauge, and infared reads 175 on upper hose. Most likely the sporadic temp readings on different areas of the radiator at the same time means partially clogged radiator.

 

Sounds like its possibly a bad Coolant temp sensor if the guage reads that its overheating but the temps you posted look normal, double cheack the thermostat, sometimes they go in backwards since the t-stat is on the lower hose it gets installed the opposite direction on a t-stat on upper hose. It doesn't sound like much but it does matter, previous owner of my jeep put the t-stat in backwards and vehicle would run for a bit then the temp would skyrocket, I had a Grand Cherokee witht he same 4.7 and after some research I learned that those motors had a major issue over heating and warping cylinder heads.

Chris

 

That's not normal. The only time mine ever got more than a needle-width above the mid-point was when the 'stat was sticking closed. Could be the sending unit or the gauge. Keep us posted. You have an e-fan and the mechanical fan?

 

Please do a search for over heating 4.7s here on the site as there are many threads. Certainly you want to check for low coolant, bad stat, air in the hoses, bad rad cap, upper and lower hoses to be hot.

Overall you may have a blown head gasket or cracked head causing it to over heat and that is what is normal for 4.7s unfortunately

 

Excellent point I didn't even think about the cooling system being a sealed system. My Jeep cracked a head when it was overheating.

Chris