Mitsubishi Pajero: 6G74 Timing Belt Failure on Interference Engine

The 6G74 3.5L SOHC V6 petrol engine fitted to V60 and V65 series Pajeros is an interference design, meaning that if the timing belt fails the open valves will contact the descending pistons, causing immediate and catastrophic internal engine damage. Mitsubishi specifies a 100,000 km service interval for the timing belt, but belt condition degrades faster in hot climates or if coolant has contaminated the belt housing via a leaking water pump — a common failure mode on this engine. Many examples have unrecorded service histories, and a belt that appears visually intact may have hardened backing that is internally cracked.

• Engine cranks but does not start (belt has jumped or snapped)
• Loud rattling or slapping noise from the front of the engine at idle indicating belt slack or tensioner failure
• Visible coolant contamination on the timing belt if the water pump has been leaking
• Catastrophic bent valves and damaged pistons if belt has already failed — confirmed by compression test showing zero compression across multiple cylinders

Ask for documented evidence of a timing belt replacement with mileage recorded. Check the water pump weep hole beneath the timing cover for evidence of past or current coolant seepage. At any service interval near or beyond 100,000 km without documented belt history, treat replacement as mandatory before purchase. If a workshop inspection is possible: Remove the upper timing cover inspection plug or cover and visually inspect the belt for cracking, fraying, glazing, or contamination.

Parts involved: Timing belt.

$900 to $5,500 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, 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 timing belt, tensioner, and water pump been replaced, and can you provide documented proof with the mileage recorded?”
• “Has the vehicle ever had any starting failure or unusual noise from the front of the engine?”
• “Was the water pump replaced at the same time as the last timing belt service?”

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.