06 6.0 blowing water from coolant fill cap

[TBoltonf250]

My 06 6.0 with 73000m when towing at peak out put will blow water from coolant fill cap (cap is good) With no load i can not make it blow out water it will only do it under strain at max boost.I can drive it 500+ miles continues with no load and it will not blow out any water.Are my head bolts stetching under pressure allowing compression to leak to the cooling system and resealing under normal driving conditions.It runs perfect no smoke steam are anything else.Can any one steer me to what is causing this?

[VeeDubTDI]

You hit the nail on the head. You can either keep driving it and hope it doesn't get worse, or upgrade to studs and MLS gaskets.

[6.0GitRdone]

Friend of mine had the exact same symptoms on his '05 dually. Truck would only blow coolant when towing heavier load (his triple axle 5th wheel camper). Brought it to the dealer under the 100k engine warranty and they couldn't replicate the issue unloaded and were dodging the bullet. So, he brought it to the dealer with the trailer in tow to demonstrate to them the exact problem. They replaced the bolts and gaskets after that.

[Fordowner14]

Just took my 06 to dealer for same problem and the head gasket was starting to go. Up graded the turbo, bolts and gaskets.