Items I changed with new:
Radiator, radiator cap, water pump, all hoses, Thermostat, Engine coolant temp sensor, and coolant temp gauge sensor.

My problem is when driving its great. Needle stays a 1/3 mark and doesnt really move much no matter what. AC Running or Heater running.

But when I stop to go into the store and come out 10 minutes later and start engine......The gauge is just below the RED. Then I start driving and goes back to 1/3

Why is it heating up when not running? I couldn't find any info on this particular problem.

 

thermostat sticking maybe? try swapping another in...

as far as why it heats when not running, this is called heat soak, as the engine runs coolant is passed through the motor to cool it, when the motor shuts off, not coolant flow to cool down the motor so what ever heat is created by driving does not get cooled quickly

 

Oh, I did thermostat too. I forgot to put that.

 

I didnt replace it at first and had the same problem. So I tried a new one but problem still the same.

 

I accidentally broke the sensor for the Engine coolant temp while putting in a fuel filter. Drove truck maybe 5 miles with check engine light on and has hesitation and back fire.

Checked the code and it was # 22

Then I saw I broke the plastic end of sensor. So I replaced it and the coolant temp gauge sensor plus everything else.

The gauge was jumping around a bit still from 1/3 to 2/3 when driving. So I changed the thermostat. That fixed the temp to 1/3 on the gauge and ran perfect.

But still heats up when turned off. Can't figure out what else is wrong. Can the brand new sensor be bad?

But I smell coolant when I restart the vehicle like it is really hot like gauge says.

 

Mine does this same exact thing maybe someone can help.

 

Your fan clutch is bad.

 

a new fan clutch wouldn't hurt.

 

X2 on the fan clutch:
- http://www.barneymc.com/toy_root/techneek/fan_clch.htm
- http://www.4crawler.com/4x4/Docs/FanClutch.pdf

It is the fan clutch that moves air through the radiator when you are not moving.

 

After I start engine when heated up I take about 5 miles or less and the temps goes back down to 1/3

I can't imagine the engine heating up and cooling down the coolant that many degrees in minutes.

I thought it might be the sensor........Since other problems would come up if it was actually overheating.

 

x3 fan clutch

 

When the truck is off why would it be the fan clutch?


The temps are great when driving. Once turned off and left for 10 minutes then restarted the temp will be high.

 

the fan really isn't working well but air is still moving through the radiator right so it cools your engine while your driving. When you start your truck up after you get back and the temp gauge is high you should hear the fan engage and roar while driving. Tell you what if you wanna be sure about it go drive in traffic or on the highway and let the engine warm up. park it and pop the hood. reach down and see if the fan has resistance meaning you can't or can easily spin it. If it free spins easily you need a fan clutch. if not and it doesn't then you have other problems. Or if you run it to operating temp and drive around and just sit and let the truck idle not turning it off you should be able to hear the fan. Trust me there is a difference i noticed when i replaced mine.

 

Will try later today.