My water pump was replaced along with new belt in march 2016. It has a new thermostat and the radiator was flushed out. When driven for some distance the water will boil out of the overflow tank but the temp gauge is in the normal range. A new cap was put on 3 months ago and the fans are working. Please help. We make a lot of out of town doctor appointments. I am stumped. Could the transmission be overheating?
RESPONSE
The fact that you mentioned “water” makes me wonder if water was used in place of coolant. Water has a lower boiling pint than coolant. If the coolant is less than 50/50 water and coolant concentrate, it will boil. If this is the case, replace the cooling systems “water” with Coolant.
If this is not the case, there may be a sticking thermostat (even new ones can do this) or the cooling system needs to be bled. But generally an overheating indication of the temperature gauge will occur with this.