What would cause a flat spot in a built 6.7

[Secretweapon07]

I no that the head gasket is blown and when I started to pull the head off I noticed that on the 6th cylinder push tubes one was off the lifter and sitting flush with the bottom of the head. Any suggestions thanks

 

[Compcowboy]

Somebody done some work before on it?

 

[Secretweapon07]

No it was bought off the lot and all work done my self it has 120hp nozzles built cp3 smarty and a few other things

 

[Secretweapon07]

So far it's a blown head gasket and a bent push rod