well blew another head gasket the other day....i talked to one of my parts guys and he said he had heard of a bad casting wich made the heads weak in the early stages of the 6.7...was wondering if anyone had heard of this

 

Havent heard it, but my HG is blown in my 09.

 

I have heard the whispers in the winds too.

 

aside from extreme boost and drive pressure i dont inderstand how a studded, fire ringed head can pop a gasket...

 

yeah i dont understand either?.....ive been looking at this thing alot i have noticed where the coolant overflow goes into the bottle is seperate from the bottle untill it gets to the bottom then it opens into one peice....now when the ruck is cold the rad is full and the bottle is at the right level...after driving the truck the bottle rises maybe and inch but where the overflow tube goes into the bottle there is an air pocket almost to the bottom of the bottle...now the truck will only bubble if that air pocket reaches the bottom oif the bottle it doesent do it all the time tho? now if the truck does bubble....let it cool down and then the airpocket is gone the coolant is sucked back into rad.....rad is full no pressure is built up in the rad and the bottle level is back where it was????? HELP ANYONE

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truck will hit 55psi on hard pull and right around 60-65 psi drive pressure max

 

umm..... just a question brk I am sure you have probably already done this ,but have you replace the rad cap/thermostate?

 

yeah i have tried both

 

i hope not any bad head castings mine has been holding well. Guess i will have to keep my fingers crossed

 

well how hard do you run yours?.......i beat the living **** out of mine everytime i drive it

 

well just got a call from the shop thats studding mine, he sent the head out to have it flux'd and they told him there is at least a dozen hairline cracks in conspicuous places on the head. they have found all of them and none of them seem too threatening. they say that the cracks shouldn't worsen, and that none of which will leak compression, boost, or backpressure. he is going to put the head back on and told me to not be concerned with it. ps the high tensile arp studs are outrageous. over 1000.00 dollars for the studs alone.

oh and the machine shop also told him that my head gasket has been leaking for some time, enough that it actually( no BS) wore grooves in the head almost 4 hundredths deep... also they measured all of the head bolts to find that 6 of them are stretched significantly... yeehah