93 blazer overheating, no heat, coolant boiling out of reservoir Help!

[Feelinbeefy]

Recently My Blazer has been acting up. The blazer is overheating, and the coolant is boiling back into the reservoir, plus coming out of the reservoir cap. There is also no heat. It is blowing cold air. What could be causing this. I am thinking about replacing the thermostat. Could that be the problem. A month ago I replaced the heater core, and recently had the EGR valve cleaned for carbon buildup. I do not think the heater core is clogged, and I have never used dexcool.

[ofcmlong]

Three easy things. Make sure your radiator is filled, replace the thermostat and flush the heater core. If either one of them is blocked it could cause the problems you are having. Also I had a Ford Probe with the same exact problem and it was leaking coolant. It would over heat, no heat, and boil over because the engine got way to hot because there was enough coolant in the system.