Just put in a new radiator on mu 02 blazer. I filled it up with coolant and water, and I then turned the engine. After about 5 minutes of idling the engine kept getting hotter and hotter. I turned it off before it got to any dangerous level. I don't know what the problem. Could coolant not be getting to the engine? The hoses are brand new also. Anything could help.

 

Have you checked your thermostat?

When you say you filled it and then ran the motor, did you have the cap off so you could add coolant when the radiator burped air?