still white smole after egr cooler/ overflow cap popping off

'12 maxxforce 10

Blowing white smoke 2 weeks after egr cooler replaced . 2nd cooler. Hose from overflow tank to egr cooler keeps leaking at egr cooler fitting, has always leaked . After this last cooler was replaced, fitting was replaced and resealed, it stopped leaking for about 3 weeks, now its back.

More concerning, radiator cap has popped off twice. Dealer pressure tested system and it popped off at 9psi looking for coolant leak. Previous to that it popped off , i just thought the dealer never tightened it.
What are they missing? Could it be a head gasket? Truck doesn't overheat and runs ok.

Replaced with updated crank case breather inlet due to turbos coking and passing oil. Turbo (it seems) has recently been making a high pitch whine under load, comes and goes. They inspected the hp turbo and said it was not coked and spins freely, but i still think i'm using oil, no external leaks.

Dealer wants to replace the intake hoses to see if unusual intermittent whine goes away

 

hey Heavyd. its 350 hp, i might be losing trace amounts of coolant but i haven't had to add any since the egr cooler was replaced. Before that i was long 3/4 gallon a day. no external leaks except that fitting on the egr cooler to overflow reservoir. Why does that fitting keep leaking and what do you think of my overflow cap popping off at 9psi? that worries me

 

It's is the fitting, hose was changed and clamp was changed from spring style to worm style. I'm pretty sure it's smoke, does it when it's warm out. Truck had been sitting for 3 weeks. It's not terrible but I see it out of the side mirror. In the past before the other cooler or egr valve was done it would pour out like a fire extinguisher.