Isuzu D-Max: 4JJ1 Timing Chain Elongation & Cam Timing Drift

The 4JJ1 3.0L diesel timing chain stretches at high mileage (typically 150,000 km+), causing chain rattle on cold start and progressive cam timing drift. The variable valve timing system amplifies the effect, leading to stored codes P0016 and P0017 (cam-to-crank correlation faults), rough idle, increased smoke, and power loss. If left unaddressed the chain can skip a tooth, causing severe engine damage. Primary drivers are infrequent oil changes and the use of non-OEM specification oil reducing chain lubrication.

• Metallic rattling or clattering from front of engine on cold start, fading as oil pressure builds
• Check engine light with P0016 or P0017 cam-to-crank correlation fault codes
• Rough idle and increased exhaust smoke at startup
• Noticeable loss of low-end torque and power
• Occasional misfires logged across multiple cylinders

1. 1

   Cold-start the engine and listen for chain rattle from the front timing cover during the first 10-20 seconds.

2. 2

   Scan for P0016/P0017 codes even if the MIL is off.

3. 3

   Check service history for oil change intervals — chains stretch faster when intervals exceed 10,000 km or incorrect viscosity oil is used.

4. 4

   Inspect dipstick oil for metallic sheen or dark sludge.

Parts involved: Timing chain.

$2,200 to $5,000 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 chain or timing kit ever been replaced, and if so at what mileage?”
• “What oil specification and brand has been used, and how often was it changed?”
• “Has the vehicle ever had P0016 or P0017 fault codes stored?”

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.