At times when i have the heat on it will all of a sudden get as cold as ac and my temp gauge will go from cold to hot and all of a sudden my oil light comes on also. I turn the truck off and crank it back up..everything is back to normal and the heat begins to work again. Is this thermostat related or what?

And I am not low on oil!

 

maybe thermostat related, hows the coolant look?? need flushing? is it full probably the thermostat though

 

yes coolant is full

 

probably needs a new thermostat

 

is it very difficult to put in?

 

nah i just did mine not to long ago,

mines a 4.6 same body style as yours, just take off the 3 bolts that hold the power steering pump on, then take the intake off, and move it out of the way, then undo the hose going into the block and undo those 2 bolts and take the old thermostat and rubber o ring out and put the new one in (like 7 dollars at a parts store) make sure its lined up right or youll need a new thermostat like i did then tighten it down good and tight then put everythign back together and start the truck and see if you have any leaks if you do it probably needs tightning (i didnt tighten mine enough) then refill the coolant cuz you will more than likely lose some

 

thanks i will try that......does it hurt the truck to run like that when it never gets to operating temperature after 15 min. of driving?

 

nah, it should take longer than 15 to get warmed up, either way it doesnt hurt to change the therm. takes a trip to the parts store breaking a 10 dollar bill and about 10 minutes out of your life good luck and hope this fixes the problem