- Faulty head gasket: A blown or damaged head gasket can allow coolant to seep into the cylinder head.
- Cracked cylinder head: A crack in the cylinder head can also cause coolant to leak into the combustion chamber.
- Faulty intake manifold gasket: A leaking intake manifold gasket can allow coolant to enter the engine's air/fuel mixture and eventually reach the cylinder head.
- Other possible causes could include a faulty cylinder head bolts or coolant crossover tube seals that could compromise proper sealing and result in internal leaks between different components including combustion chambers.