So maybe the wiser crowd down there can shed some light on this.
Aug 2018 this thing puked the head gaskets and I put in Fel-Pro ones along with ARP studs, complete set of new bosch injectors, 3" down pipe, a billet turbo compressor, blocked off the egr, pcv re-route, airaid air filter, a bulldogII, dsp5 and a 150+ tune from a guy in the USA (was supposed to be reputable guy).
Within three months the back of the head was leaking coolant if I ran in the High tune and would stop with normal DD. Was rare for me to use that level anyway so no big deal, as I mostly haul a trailer around.
Three days ago it puked the gasket again (yeah i was in the high tune, it was a jag type 4 and I had to wipe the smirk off his face).
So the things I found taking it apart were:
-No oil in the intake anymore (this is good as I had some before)
-Very fine sand in the intake all the way up to the turbo
-Half the head stud torque was below 125 some as low as 90
-Head was decked down .012" to get it flat again (he said mostly in the middle)
-There was black between the cylinders like there had been bridging during combustion
-Two of the injectors were way over the balance limit the rest were fine.
Any ideas?
From what I've read and what the folks around here say the cause is apparently everything from the timing being wrong to the nut behind the wheel being loose (no body in Ontario knows a bloody thing about the duramax, but they all think they do)
I called ARP and they said some brands of gasket need to be re-torqued to work correctly. I'm seeing some folks online saying the studs need to be torqued and backed off 4 times and then sit for 24hrs and re-torque again. They are even citing real ARP documentation for this procedure though I can't find a single thing about it myself on their website.