Toyota Land Cruiser: 1FZ-FE 4.5 Petrol Cracked Cylinder Head and Head Gasket Failure

The original 1FZ-FE cylinder head casting has thin material sections between the exhaust ports on cylinders 4 and 5, which are prone to thermal cracking under sustained high-load or overheating conditions. A crack in this area breaches the combustion chamber, allowing coolant ingestion and exhaust gas entry into the cooling system. Toyota acknowledged the issue and released a revised cylinder head casting with improved port bridge thickness, but many early 80 Series vehicles still carry the original susceptible head. Unlike a typical gasket failure, a cracked head cannot be repaired by gasket replacement alone — the head itself must be pressure-tested and replaced or sleeved by a specialist machinist.

• Persistent white steam from the exhaust at operating temperature, indicating coolant burning in the combustion chamber
• Coolant reservoir bubbles at idle with no external leak visible, caused by combustion pressure entering the cooling system
• Engine misfires or rough running on cylinders 4 or 5 as coolant disrupts combustion

1. 1

   Conduct a combustion leak (CO2 block) test on the coolant system with the engine at operating temperature.

2. 2

   Check the oil filler cap and dipstick for white emulsion.

3. 3

   Inspect the exhaust for persistent white steam.

4. 4

   Ask whether the head has ever been replaced with the revised casting.

5. 5

   Verify whether the engine has any history of overheating, which accelerates cracking.

Parts involved: Cylinder head, Head gasket.

≈A$2,760 to ≈A$5,980 at independent workshop rates, shown as an approximate guide in Australian dollars. That is for this job on its own, not for the car.

An estimate, converted to Australian dollars, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

• “Has the cylinder head ever been replaced or has a machinist pressure-tested it?”
• “Has the engine ever overheated, even briefly?”
• “Is the revised Toyota cylinder head casting fitted, or is this the original head?”

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.