PSI-FX4

I had to add maybe a pint in my 2012 Ecoboost at 60k miles to get it in the middle of the cold range. To me, adding a little once a year or something is pretty normal in just about all my vehicles I have ever owned.

Koolponycar

Burns one place to look could be the quick connects on the heater hoses. They have o rings inside and can weep ever so slightly and dry or evap on a hot surface.

papa tiger

Look for a discolored trail, it is evaporation of coolant. A bore scope might show a very clean cylinder piston evidence of steam cleaning. Taking a look at cold coolant level is ohhh soooo important during service. : >)

93Cobra#2771

iTrader: (2)

I had a similar issue and couldn't find where the coolant was going. No drops on the ground but could occasionally get a whiff if it.

Ended up being a thermostat housing leak. Not enough to ever make it to the ground.

papa tiger

A good light an small mirror can help. I like the one with red an green beams with it.

Grump

I had a slow leak when the truck was brand new, had to go to the dealership multiple times they could not find anything. After one of the Techs said guess we'll have to wait for it to get worse? I got frustrated and after speaking to the service manager they added a UV leak detector to the coolant.

The next night I used my own UV light(I am a HD mechanic) and found the leak was from around the threads of the block heater. Went back to the dealership they replaced the block heater and flushed and refilled the coolant system. The leak was very slight even under pressure and with the location of the block heater and my truck having skid plates( FX4) it was not an easy thing to spot. Good luck.

Burns331

Yup, going to have to add just a little bit of coolant. Its been several months, and the level in the tank has dropped maybe 1/2" so its not alot. Just odd. I need to try the UV light trick.

TJPlatinumEB

I've seen a number trucks, both EB and 5.0, have this issue and it ends up being the coolant reservoir itself. It is all one piece with the lower half of the intake box and somehow it ends up cracking near the bottom and either soaks into the wheel well liners or only leaks when it gets hot enough to expand the plastic enough, in other words only while driving.

Had a friend just have to replace his on his 2012 EB for this exact thing.