Cold climate Montero Owners

[mapper]

With that much coolant disappearing you'll find the leak eventually. Many times with coolant is evaporates quickly at the source of the leak while engine is warm. Look for white crusties as a tell tale sign. The other thing is to wait until the engine is cold then take the cap off the radiator. Once the cooling system cools down it creates a bit of vacuum, when you open the cap, the leak will start. Of course, the other step is to pressurize the system while cold and look for the small drip of coolant.

Edit: I've heard folks mention the coolant crossover hose, no the back of the engine, under the intake manifold :-( as a relatively common leak location on these trucks. Given your comment about finding coolant at the trans cross-member, I'd definitely look closely there.

 

[jeep-N-montero]

A commonly overlooked area that can leak is where the heater hose connects to the core at the firewall, the hose becomes brittle and cracks due to vibration, hard to see it drip sometimes.

 

[KarmannMarco]

Well this morning I had about a cup worth of coolant in my drip pan I put under the truck last night. Parked on my gravel driveway Ive never noticed any fluid under the truck in the morning and because everytime I work on it in the garage I can never get the leak to happen with the engine running/warm. So whatever it is , it's happening when the truck is cold parked outside because yesterday I had it running/warm for about 2 hours while I was looking for this leak and I couldn't see a drop anywhere. I'll have to get ahold of a coolant system pressure tester and take off the intake manifold to get a better view of things. Thanks for the suggestion guys.

 

[mapper]

A commonly overlooked area that can leak is where the heater hose connects to the core at the firewall, the hose becomes brittle and cracks due to vibration, hard to see it drip sometimes.

The impetus for the initial post suggests that the heater core is, at times, getting air rather than coolant...before eventually, somewhat, burping itself. So I agree with this. Something connected to the heater core is a high probability location. Based on everything said, I have high faith you'll find the leak somewhere between the motor and the firewall. Get a good light and a telescoping mirror and look for white crusties. You many find something that is manageable without removing the intake. Though taking intake sure makes access easier.