tonydutt

Guys,

Trying to figure out this problem I have been observing recently:

Every now and then I get a smell of anti-freeze in the cab - it smells like it is burnt almost. I noticed it when I drove over the same bump on two separate days and, after opening the windows and evacuating the cab, the smell did not return.

Here is what I have observed:
- the coolant level is below the cold level mark - it has definitely gone down.
- No coolant leaks outside or inside I can find
- No stains or puddles on the inside on or under carpet
- Can't feel any moisture around HVAC box as far as I can reach
- For a couple of months I have thought I smelled burning anti-freeze, from the outside when I get out of the truck after shutting down. Now the very strong smell on the inside during operations is making diagnosis difficult.

2009 F150 King Ranch, 5.4, 4x4 - 156,000 original owner. All maintenance done by Ford during warranty through 100,000 then by me. Related maintenance:
- replaced the sensor on the side of the HVAC box for fan speed control (4 years ago)
-replaced all the blend door motors (pain in the butt) 3 years ago
- flushed and replaced the coolant with Motorcraft pre-blend (2 years ago around 110,000 or so).

Any thoughts on problem this may be? Similar experiences?
Heater core is my guess? Why does it appear inside only when hitting a bump and not when heat is on all the time?

Anyone replace a 2009 heater core - I don't see a good video on YouTube for 2009-2014 F150. Plenty on older trucks. Any special parts, o-rings, clips, disconnects or gaskets to get in addition to heater core? I will replace all blend door motors again.

Thanks,
Tony

kbrock

That would be my guess too, a leaking heater core