Hey guys. After getting my intake gaskets and heater core done, I've been driving the car a bit more. I took it on a 1.5 hr round trip highway drive the other day and it ran great. Everything was fine.

Then I went out the other night when it was cooler out and when I got home, I smelled coolant. Popped the hood and the overflow tank was 3/4 filled and spilling out the top on turns. It also didn't seem like the radiator was sucking all the coolant back in once the engine cooled down.

Decided to take it to work this morning. It's pretty cold here ~40 degrees this morning. My drive is like 6 miles to work. I notice halfway there that I have like zero heat. Then I look at the temp gauge and it is getting up to H. I've never seen it that high. I put it in neutral and turned the engine off as I coasted down from 60. I watch as the temp gauge starts dropping immediately. Put the ignition in run and pop it into 4th to start the engine up again, and I have heat!

Pull into work and see steam. Fearing the worst, I pop the hood and the overflow tank is full to the brim and has overflowed onto the frame and my exhaust.

What is going on?? How could I have no heat, yet the car is basically overheating? Then I get heat back and the overflow tank is overflowing? Air bubble in the system? Bad radiator cap? Overfilled it with coolant?