i just replaced my radiator tonight and me and a friend drove around for at least 5 hours and then on the way home i happened to notice that the temp gauge was on cold. after it was running at the right temp for that long. I turned the heat on and it was blowing cold air. does that mean that something is wrong or is it just the gauge. thanks in advance

 

any body i need to drive the car tomorrow to work and i dont want to overheat my engine

 

I trust you filled it up with coolant, tightened all the hoses and all that good stuff?

And the levels are still OK in the overflow tank?

You drove it for 5 hours and it didn't show temperature or seize up?

Tough to say without digging around under the hood, but are you sure all the sensors are still hooked up?- that still wouldn't explain the heater not working though...

How far away is work? if it survived 5 hours in this state, I'd think it's either about to die for real or it's probably fine to get you to work.

If the temp was OK for a while but now it isn't, and you didn't pop a hose or have some other massive coolant loss of some kind, you probably had a lot of air in the system that got burped out during your drive.

Double check the levels, I'd expect to find it a few quarts low, top it off and you should be OK.