The cylinder head is an important component of all combustion engines. When it cracks, it can cause catastrophic damage to the engine.
Even new cars are subject to cylinder head cracking, especially if the cylinder head was installed improperly or it had weak points in the metal.
One of the main symptoms of a cracked cylinder head is overheating. If your car is constantly overheating, coolant may be leaking as a result of a cracked cylinder head.
It is not uncommon for oil to leak out of the crack in cylinder head. Motor oil leaking from your engine could be a sign of a cracked cylinder head.
When your cylinder head is cracked the amount of pressure produced by the head is drastically reduced. A compression pressure test should show that pressure is greatly reduced.
A crack in the cylinder head may allow combusting gases to leak out. This can be seen by smoke emanating from the engine.