so im drivin and look at the temp gauge and it goes almost all the way to the top, so i turned on the heat and it went back down...but i kept driving and again it went back to almost the top and then fell back down to the middle....it was doing this all day, gonna check the themosat tomarrow...anything else i should check for????

 

coolant.

 

are u leaking coolant? u should check for that... i did this before when i'm idling it goes up but when driving it goes back down..

 

^^

 

common causes of overheating:
-air in system (bleed air from system)
-external leaks (visual inspection-etc. rad., water pump. cap, hoses)
-fans not coming on (bad relay or circuit)
-dirty coolant (drain and fill system with new coolant)
-blown head gasket (inspect oil and coolant for mixture)
-thermostat stuck closed (upper hose will still be cold upon normal op. temp)