Hi my name is Chris. I drive a 91 cougar with a 3.8 engine. Lately the heater in my ride doesn''t put out any heat. I replaced the thermostat, which didn''t solve the problem. I only drive to and from work (a couple of miles each way). Sometimes it puts out heat and most often it doesn''t. Coolant level is fine. Is this my water pump going bad?

 

do you know the engine is warm? if you''re not actually on the road for more than 5-10 minutes, it might not have enough time to actually warm up. If it does get warm, check the hoses going to and from the heater core to make sure they are warm. if they are not warm, there may be a blockage in the heater core. there may also be a vacuum actuated valve inline to the heater core if you have an automatic climate control system (like what''s in my 88 MGM). With the Ford water pumps, they usually die by breaking seals and leaking/spraying everywhere. It''s rare that the impeller stops working, but it has happened. If you have a temp gauge on your dash, you should monitor that, and when it gets to the normal zone, check the radiator hoses to make sure they''re warm too. If they are not good and warm, there may be a pump issue. If you have a radiator that has a cap over the high side hose, you can verify this by leaving the cap off and starting the car. when the thermostat opens you should see some flowing (or light overflowing). If nothing happens or the temp just keeps climbing past the center of the normal range, you have a pump/thermostat problem. I know you just replaced the thermostat, but sometimes they don''t work or break soon.