Originally Posted by TexTruck
No is the answer to determining what caused the initial gasket crack. Any suggestions? I will take you advice though in regards to the head removal. Thanks again!
Well., ideally you determine what the root cause was BEFORE teardown, but it seems we're past that point, so...
First we have to determine if the old head gasket gave up due to overheating, improper assembly or possibly old age. You can substantially figure out the last two simply by knowing the mileage on the engine and the repair/maintenance history of the vehicle. You just bought it so you may not know either.
That being said, a set of experienced eyes looking at the engine components as they come apart can give you volumes of information. Are there fasteners missing and hose or electrical connections cobbled together? Those (and others) would be a sign of sloppy workmanship that if the heads had beed off previously could most certainly lead to a blown head gasket.
On the other hand, does the oil smell burnt and is it caked inside the top of the cylinder head? What do the coolant and the cooling passages in the block look like? Has the wax pellet in the thermostat literally exploded from heat? Is there even a t-stat installed? These would be signs of an overheat condition and in the case of the last one, someone misguidedly attemting to "rig" the engine so it won't.
Basically you have your homework cut out for you. At a minimum, I recommend replacing the t-stat and flushing the entire cooling system before you start the engine and then bleed it a fast as you can after start-up and watch the temp guage and troubleshoot it from there.
P.S. What did the "mechanic" who diagnosed the blown head gasket say caused it?
P.P.S. Before I hit submit, I thought of something you may be unaware of. If the engine was overheated, they are sometimes overheated to the point that the pistons scuff and the rings lose their tension. If that happens, the engine will never run correcty if it'll run at all until it's been re-ringed at a minimum. It'll also smoke (burn oil) like a chimney.