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As these cars accumulate higher and higher mileage, some different problems are starting to crop up such as cracking of the Cylinder Liners, most often, the #2 and #5 cylinders.
This is thought to occur because the mettalurgy becomes more brittle after long-term heat cycling (or excessive overheating - watch that cooling system, especially cleaning the radiators and insuring your fans operate correctly) and the slight torqueing the engine experiences (a good reason not to ignore the condition of your motor and transmission mounts).
Usually beginning as parallel cracks at the top of the liner, these often join further down the liner. When engine torque is applied, a 'D' shaped chip can break off the top of the liner. Somewhere in this process the integrity of the water jacket goes away allowing coolant to enter the cylinder creating Hydrolock, or allowing the coolant/oil mixture to attack the Main or Rod bearings.
Often this is the cause, but it frequently goes undiscovered because the diagnosis of Engine Replacement is made w/o a total dismantling of the engine and is attributed to other issues such as timing chains etc. which may in fact be secondary failures caused by the bad cylinder liners.
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