Why no heat after replacing thermostat on 1993 Mercury Villager?

Answer 1

Does the heater work when you go down the road and stop when you come to an idle? If so, I had the same problem several years ago with my 1993 Mercury Villager. The water level is too low. Although the radiator appears to be full, you have to bleed the system. On the top of the intake manifold (Center) there is a small bolt that needs to be taken out. It's very hard to get too and don't drop it! The bolt is above the radiator level but if you don't remove it you get air trapped in the top portion of the manifold and hot water doesn't go through the heater coil. With the bolt on top of the intake manifold removed, start your engine and slowly keep pouring water into the radiator until water comes out the hole where you took the bolt out. Put the bolt back in and tighten it up.