ICE MK A-School Practice Exam

Coolant in the combustion chamber is the clearest sign that the head is compromised. When the cylinder head cracks, the cooling system can no longer keep its coolant strictly separate from the combustion chamber. Coolant then enters the cylinder during compression and combustion, where it doesn’t burn like the fuel-air mix. That intrusion shows up as signs of coolant burning, such as white exhaust smoke and possible coolant loss, which points directly to a head crack or gasket issue.

Consistently white exhaust can happen if coolant makes it into the exhaust path, but by itself it isn’t as definitive. No change in compression is unlikely because a cracked head typically affects the seal between the head and block, often leading to compression loss or leakage. Improved fuel economy isn’t something you’d expect from a cracked head; performance usually worsens along with potential overheating.