I own a 2006 Lr3 Hse (200k plus mileage) and im having issues with coolant boiling out from the reservoir cap. It only does this after driving it for like 5 mins. First off the reservoir, the cap and the water pump, thermostat are all brand new. No hoses are leaking. I did a combustion test ( the colored dye didnt change colors) did a pressure test and it didnt lose pressure. I did a coolant flush and i had to switch from pink 50-50 coolant to the clear yellowish mix it yourself coolant. ( autozone said they no longer carry the 50-50 for my truck) think i may have done it wrong which caused an air lock?? It all began on my way home i was driving thru town about 5 - 10 mph. I heard a bubbling sound and saw white smoke billowing from the drivers side hood. The gauge went from middle temp and dropped all the way down to cold. I immediately stopped & opened the hood, the coolant was boiling out of the reservoir, the cap was still on. Towed it home. Each time i test drive it, the coolant boils out the top. What do u advise me to do ? Any help would be appreciated so much. Im trying to learn so to avoid going to the stealership. Im fairly good w tools for being a lady and at this point im ready to break out the swear jar. Haha.

 

You need to purge air out of the system, there is enough air allowing the coolant to expand and boil. Once that happens pressures rise fast and the coolant reservoir cap does it jobs and blows. There are two places to bleed air, the "t" junction next to the throttle body. Two small hoses go to it. Also that black screw onto the reservoir is for bleeding.

 

Did you ever resolve this? I’m having the same issue and haven’t been able to accurately diagnose for months.