2000 f150 5.4 4x4 there is a coolent leak a little in side i am having the steam smell and some in side truck.. look under my truck and its leaking where my tanny any engine meet.. is coming from where my heat sheld is for my pass cat.. any idea what it is? i was thinking heater core until i saw it leaking under my truck as well..

 

if you smell coolant inside the truck it is the heater core. happened to me in my 97.

 

Check the coolant lines under the hood i had some problems with mine the steel pipe went bad and rusted out before you think heater core check those first.

 

I think the drain for the air conditioner is near the trans tunnel. The heater core lives in the same plastic box, so you could have a leaking heater core that is draining down to there.

Figure out exactly where the water is coming from.

 

Its the heater core. i did test. all lead to the core.. ganna be a fun weekend.

 

Check the freezeout plugs,if thats it,you neeed to remove the trans to repair,make sure you check both sides.