The heater in my car hasn't been producing heat and the termostat has been inconsistent in temp. Dealership says I have a crack in my water pump and needs replacement. They told me replacing the water pump requires the thermostat and thermostat sensor to be replaced as well. Wondering if this is a common repair when replacing the water pump?
Water pump replacement means thermostat & sensor too? on 2002 Volkswagen Jetta
by amckinley in Lake Oswego, OR on December 08, 2009
ANSWER by patrick mannion on December 08, 2009
The water pump failure is common, the impeller on the pump fails. The temperature switch is a common failure item on VW around this year, it normally brings on a Check Engine light, when you test the switch it may test all right and only intermittently fail. Replacing the thermostat then is just added insurance that the cooling system is in tip top shape and the heater will function correctly. With the cooling system already drained to replace the pump the extra labor to replace the thermostat should not be much extra.