86 heating and cooling

[4eyeGT5.0Ho]

My 86 Mustang when summer will over heat some times and other times it will stay in the norm. now winter it will not heat up at all and i get no cabin heat. the heat gauge will only move up like 1mm if that. please help

 

[ID89GT]

Check your coolant level, may have air in the system.

 

[SVTFreak]

Also, thermostat stuck open (yeah, you read that right) can cause overheating in summer and lack of heat up in winter.

 

[4eyeGT5.0Ho]

coolant i have. ill check the thermostat . could it be my heater core?

 

[Stevebird]

86GT5.0

I am having the same issue with my 86 - I changed the stat . NO HEAT! Not that I am complaining being in Orlando _ but Damn, I moved from Michigan to get away from the cold.. Anyone have any suggestions?