I have a 2004 ram 1500 ST 2wd with 169k miles and I originally was having bubbles in the tank and was overheating but no milky oil leaking water pump radiator or white smoke from tail pipe. So I flushed the system was barely any coolant in the engine and replaced thermostat and radiator cap and ran some blue devil in it and it ran great for a month and now it's back to running in the 3/4 range of the temp gauge and fluctuates, doesn't redline but gets really close. I checked the fan clutch with a rolled up newspaper and it was still strong. Still no leaking pump , radiator, hoses or milky oil. Thoughts??

 

Where is the coolant going?

 

Not sure where it went to begin with because I flushed it about 8 months ago and filled it back up just think it's weird that everything seems to be working but still overheating.

 

Verify the temp. You can get a cheap IR thermometer for just such a purpose. See if what the gauge thinks, agrees with what the thermometer thinks.

 

Hi. Check to see if you have air trapped up by the heater core outlet hose. Try to recall how you refilled the rad when you flushed the system. Did you allow the coolant to settle and let the air bubble out? When the fluid is cold, open the cap and check the level. If low, slowly add coolant and let it settle. Check to feel the heater core hoses when the vehicle is hot but off. Are they both hot? If 1 is hot and the other is cold, you also may have a blocked heater core. You can forward/back flush the core and that will help a lot.

I hope this helps.
DDay77
John