Last week we had a cold snap and my radiator froze. I guess I overdiluted the coolant with water. This resulted in a cracked radiator. I bought a new one but am still having overheating problems. I tested the thermostat which is fine. There are no leaks. I checked the oil to see if water was getting in. Upper and lower radiator hoses are getting warm but the heater isn’t blowing hot. Suggestions?