I had to replace my head gasket twice for two main reasons...
First, make absolutely sure that the cylinder head and block are clean and free of any remaining materials. I had to take a 3M abrasive pad to get the remaining materials off the surfaces. I used brake clean to clean the entire surface. Get the entire surface area to shine with bare metal.
Second, using a good torque wrench, torque the bolts down in steps, using the pattern provided in the FSM. I stepped at 30ftlbs, 50ftlbs, 65ftlbs, 75ftlbs, 85ftlbs, and lastly 96ftlbs.
While I had the head off, get it checked for flatness, and I would also have the head surfaced by the stone ground method, not the cut method. Before you have your friend start it again, make sure that, if turbocharged, your friend has the boost set to an absolute minimum.
First, make absolutely sure that the cylinder head and block are clean and free of any remaining materials. I had to take a 3M abrasive pad to get the remaining materials off the surfaces. I used brake clean to clean the entire surface. Get the entire surface area to shine with bare metal.
Second, using a good torque wrench, torque the bolts down in steps, using the pattern provided in the FSM. I stepped at 30ftlbs, 50ftlbs, 65ftlbs, 75ftlbs, 85ftlbs, and lastly 96ftlbs.
While I had the head off, get it checked for flatness, and I would also have the head surfaced by the stone ground method, not the cut method. Before you have your friend start it again, make sure that, if turbocharged, your friend has the boost set to an absolute minimum.