Hi,
I have a 1997 F150 4x4 5.4 truck. I just developed a coolant leak and so far I have not been able to determine what it is leaking out of. Sorry I am at work and have not been able to get dirty to follow everything and determine what is going on. The coolant puddle is small and i do not have to add any coolant as of yet but soon will. It seems the puddle only is created after sitting many many hours over night. I drive 8 miles round trip to work and never see a puddle underneath at work, but there is one in the morning when i leave. Maybe 8oz if that is the puddle.

The problem
Coolant leaking from driver side from engine. It is the lower part of the engine that you have to be under the truck to see. It is about halfway from the front of the engine to firewall.
There is a single wire that is going into this plug area. It looks like two pronged plug of some sort as the cover shows two terminals. I am sorry I am not sure where this wire goes as I am at work and can't come back all dirty.
There is a recessed allen wrench bolt below it (closer to ground)

Any ideas for now would be great as it seems like it should be a fairly simple fix but without the time to diagnose it, I am not sure what it all involves.

Thank you

 

Sounds like the block heater is leaking to me. Probably cost 20 bucks or so from ford. Easy to change too.

 

Thank you Skyhigh ford!
If anyone else stumbles upon this, they can be called a Freeze plug heater also. I will probably change it this weekend when i get some time unless it drops all my antifreeze