1992 Subaru Legacy • 160,000 miles

2 of the last 3 times I drove my car it has not made any heat and blows cold air out of the defroster. At the same time the temperature gauge indicates that it is running hot. This is an intermittent problem that has just started. Is there any way to make sure that it is a thermostat problem and not the water pump?
December 30, 2012.

IF there are no strange noises coming from the pump, chances are it is fine. If you refer to our homepage under the DIY section, there are directions on how to check a thermostat. It will require that you remove the t-stat and boil it to see if it opens. You can also check by opening the radiator cap when the engine is cold, starting the engine, and waiting till it warms up to see if the water circulates.