It might just be the heater core leaking, but I'm not 100% on this one. Yesterday, I tried to use my defrost and all it did was blow up fog and smelled terriably sweet of coolant. Today, even with my heater and vents off the entire cab smelled of anti-freeze. When I turned on the heat, it got really bad. I looked and sniffed under my dash, but I did not detect anything leading me to believe it was my heater leaking. I checked under the hood at the heater core, and nothing there looked suspecious either. I started and ran it for a while with my heater off, and it smelled of it again, especially under the hood and even a little around my exhaust pipe. It wasn't smoking, but it almost sounded as if it were trying to run under water. The oil isn't milky yet, and I'm going to run a compression test tomorrow to see if the engine is blowing anything back into the radiator. So, if anyone had any insight on this one, it would be greatly appreciated.
Thanks,
KUZY

 

Thats what it is. The heater core is bad.

 

As Texasguy said--it's the heater core.

The "running under water" sound you thought you heard is the same way it sounded prior to this happening, but you were not worried then and didn't put your ear that close to the tailpipe before, and listen as intently as you did recently. The failure that makes the fogging and smell in the cab possible is NOT also able to simultaneously somehow flood the exhaust tract. Now if you had a boat with an inboard/outboard, that might be a different story.... LOL

The fogging over of the windshield, the smell, etc...--all classic symptoms of heater core failure.

Get a shop manual, and follow the instructions. It's not overly complicated, just a PITA, depending upon the year.

Also, keep in mind that some vehicles can cause SEVERE burns to passengers' feet, due to heater core failure. Not sure if the F-Series is designed in such a way that this is possible, but I can tell you that some people have been severely burned by leaking heater cores, in the discontinued Mercedes-Benz 190 series, for example.

Get it changed out--you'll feel much better. Trust me, I think I've done one in three of the four F-Series I've owned. If you're lucky, you can change it from under the hood. In my '72 F-100, it sucked, as it had to come out under the dash--laying with the back of one's head on the floor, in a std. cab, is not the most relaxing way to spend one's evening.

I can't recall the manual's instructions, but I'm assuming it would be a good idea to drain the cooling system before you open it up--and don't forget to refill it before you fire up--read the shop manual and you'll be fine.

BigSix1

 

I agree with the rest-heater core-depending on the year they are a breeze to change-if it's a 87/88 they are right behind the glove box-maybe 15 bolts/ screws max-the one thing easy on those trucks price on new ones vary -the hardest thing i found was getting the hoses off-the rest was so easy-call a few places if ya got them in the area and price em out-good luck-piece of cake!