A week ago I was driving and realized that my heat was not working and only blowing cold air out. So I checked my anti-freeze and noticed it was drastically low. This seemed weird since I had filled it within the past 3 months. I bought more anti-freeze and filled it completely with a full gallon. I know that if your anti-freeze is gone it is either going one of two places, into your engine or onto the ground. I checked my dipstick and found no milky white on it so I don't believe there was any leaking into the engine at that point. I then took my explorer to two different mechanics who pressure checked it up to 18 lbs and there was no leak. My problem is the anti-freeze obviously leaked somewhere and I cannot figure out where and neither can anyone else. I am afraid it is into my engine and do not want have my engine fall apart because of this. I have been told I could possibly have a blown headgasket by a mechanic I trust who isn't near me though and cannot check the car. Has anyone had any issues like this or does anyone have an idea what could be going on? Any information would be greatly appreciated! Thank you!

Coolant could be looking into the combustion chamber- you won't find it in the oil that way. The symptom of that could be white smoke from the tail pipe most of the time.

I deleted your other post- just one is enough around here.

Would that be something a mechanic could find fairly easily? No one has been able to find a leak thus far and I need to catch this asap before something more serious happens.

If a cooling system pressure tester was hooked up, they might find the leak

even I have one of those--

If the heater core is leaking, it will slightly drip on the passenger side downstream cat converter and the liquid will evaporate before it can accumulate into a puddle on the ground. You might check this out--
look under the area where the antenna cable goes through the firewall for signs of dripping.

It's not the end of the world- keep water/antifreeze in it and it can run forever. The best thing to do is let your engine get to operating temperature, open the hood and watch for spraying coolant. My wife's car was loosing coolant, never could find any puddles, but it always needed water- a heater hose failed and was leaking under pressure.

Maybe someone with a 4.0 has had this problem can jump in here and offer some advice :dunno:

Edit: I am assuming its a 4.0??

Maybe someone with a 4.0 has had this problem can jump in here and offer some advice :dunno:

Edit: I am assuming its a 4.0??

I have the same problem; a very slow leak that doesn't appear to go anywhere.

I planned to get on it this weekend actually, but nobody had a decent pressure tester, and I was also going to get a UV dye kit but couldn't find that either. :confused:

I do suspect it's a head gasket; right before I got it, my dad said the Explorer overheated during a drive across Texas. I hear the Explorers are susceptible to head gasket damage. There is a very slow oil leak too, even less noticeable than the coolant, but it's there.