im having some overheating problems..after about 20 mins of driving my car it starters to overheat..but for some reason it jumps from all the way hot and goes back to mid mark at idle..whats up with that..no white smoke while i drive..no sweet smell like im burning coolant..i figure out my fans werent cuttin on so i jumps the plug so they stay on..but im still getting the same problem...could it be bad radiator or water pump..if so i can i tell..please help thaanks

 

you have an airbubble

or you didn't put your tstat in and while the car is moving (rev"ing) the water pump is pushing too much water for your radiator to cool the water.

make sure your tstat is working