my car is heating up i just put in a thermostat hod do i no if i need a new radiator

 

More details! How's the headgasket on your motor? What year? What motor? What car? If it's blown you'll be leaking oil and coolant and be blowing out white smoke, is there any? Pictures and more details..

 

All depens on your setup. If it's a stock motor just check your thermo, if it's not working properly replace it. Bleed the radiator and put in new fluid. Water Wetter is good stuff.

That will eliminate most common over-heating problems.

 

Don't make 2 threads for one question dammit..