We have a 2006 PT Cruiser. Within a year the Dodge dealer has replaced the heater core five times. They say it’s a defective part each time, but I’m not so sure. Does anyone know if something else is afoot?
Usually the core gets a leak after the car has been driven, then parked for a few minutes. When we restart it the heater core blows sending antifreeze vapor out the heater vents.
Has anyone bothered to check for a breached head gasket?
If compression gases are leaking into the cooling system, it is possible that they could be providing enough pressure to cause a leak in a badly designed/cheap/poorly-manufactured heater core.
If it turns out that the head gasket has been breached, then you have a very big decision to make, namely–whether to repair it or to junk the car, because there could be bearing damage in the engine as a result of a head gasket breach.