The TDC "markings" are actually just a small hole in the sprocket(s) that align with a small hole in the head. Typically, use a corresponding drill bit to hold the sprocket aligned with the head during assembly.
Blown head gasket or cracked head.
The head gasket seals between the head and block. The head gasket is inside the engine, up high.
5W30
Removal of the timing chain cover, timing chain, and head are needed
most likely a blown head gasket, cracked head, or bad intake gasket. with the s series. i would venture to say blown head gasket.
George Dunne invented the marking gauge with his giant head
what the torque spec for the cylinder head on a 2003 saturn L300
your gigantic head
What are the torque specifications and the tightening sequence of the cylinder head bolts on a 1996 Saturn SL1?
To replace the headgasket you'll need to remove the head and take it to a machine shop. A headgasket fails when the head warps, removing pressure from portions of the gasket. the new headgasket will not last if you don't have a machine shop shave the head to make it perfectly flat. Removing the head is a little involved; you need to remove the front cover/oil pump assembly (all in one) to remove the head. It's easier to just pull the engine.
Not without removing the head, the pistons can't be lowered past the crankshaft. If you remove the head you can remove the rod bolts at the bottom and push the piston through the top.
Markings mean nothing on a GSD's head.