msu_johnny ... 99 grand marquis

Overheating + cooling system pressure build-up sometimes indicate a head gasket problem. *Though a pressure and/or combustion-gas test should be done on the cooling system.

Do you have oil in the coolant ?

Do you have anti-freeze in the oil ?

Alternative ... Air pocket in the cooling system.

Regarding the no-heat ... Plugged heater core and/or air pocket in the cooling system | blend-door issue (?).


-click the Vic-