Overheating only when I turn on the heater in Achieva 94 2.3L

[stangp]

Hi every one ! Help needed!

Strange thinks happend... When I turn on the heater in my Achieva 94 the temperature of the engine goes over normal, when It's off the temperature goes back to normal .

What is that?

Any help will be appreciated.

[GTP Dad]

Welcome to AF!!

Have you changed or checked the coolant lately? It sounds like you either are dealing with a low coolant condition or you have air in the system. When you turn the heater on the coolant level may be dropping so check it with the heater on and the engine running. Look inside the radiator when you turn the heater on and if the level drops then you need to add coolant.

If you have recently changed a hose or had the coolant system open you may have an issue with air in the system. This happens and once you bleed the air the problem should go away.