So...wondering why when I am cruising along and punch it do I get a slight mist inside the cab of the truck along with the sweet smell of glycol??

 

Leaking heater core?

 

Maybe the increase in pressure from a faster spinning water pump is forcing antifreeze from a leaking heater core?

 

I get this too, but on deceleration. No evidence of oil or coolant mixing in either system that I've ever seen. Haven't worried about it much because of that but I am curious.

 

my 78 and 79 have valves under the hood so the coolant doesn't always flow through the heater core. The 77 doesn't, so the coolant always flows through the core. I'd suspect you have coolant always flowing, and a leaking core

 

Like others state, more than likely your heater core is bad! Also, you might see if the carpet on the passenger side is damp and has a coolant smell. AND, "if" you turn your heater on, sometimes your windshield on the pass side will fog up as well!!

 

The vacuum controlled heater water valve (D4AZ-18495-A replaced D1AZ-18495-A) is only installed if a 1973/79 F100/350 or 1978/79 Bronco has factory installed integral A/C or the Hi/Lo Comfort Vent System.

No factory A/C, no comfort vent system, no heater water valve!

If you can smell anti-freeze inside the passenger compartment, the heater core is leaking. It makes no difference what make the vehicle is.

 

Thanks Bill! I wondered why some trucks have the valve and others don't. My 77 has the high-output heater and dealer air, so, no valve

I thought it might be a year-specific thing. Thanks always for enlightening us!

 

Well, thanks all! I suspected the core but needed the experts to confirm. Also, interesting comment from scott79....whenever I turn the heater on every window fogs up!

 

Glad the FTE community could help you out!! This isn't my first rodeo, been there done that a few times!! haha