Chevrolet Repair: heater core problem, chevy blazer, heater core

Question
I got a few questions concerning my 1999 Chevy Blazer...I have a lot of heat coming in, but my problem is the past few days I have smoke coming through every vent there is inside my car fogging up my windshield, is it my heater core? if so, how much does it usually cost to get a repair? any answers regarding this would be very helpful, thanks   
-Billy

Answer
Hey,

 The film on your window is likely coolant if it feels a bit greasy.  If the heater core leaks it will vaporize and coat the window.  The heater core comes out from the inside and is approx 90 dollars for a delco core and about 5 hours replacement depending on options.

Wayne