Nissan Patrol: TB48DE Timing Chain Stretch and Tensioner Rattle

The 4.8L TB48DE inline-six uses a duplex timing chain driving the twin camshafts. From approximately 150,000 km onward, the chain stretches and the mechanical tensioner loses the ability to maintain correct tension. The characteristic symptom is a metallic rattling or slapping noise from the front of the engine on cold starts that diminishes once oil pressure builds (typically within 5–15 seconds). As wear progresses, the rattle persists longer into warm-up and eventually becomes continuous. A stretched chain can jump a tooth under high load, causing catastrophic valve-to-piston contact. Chain guide plastic deterioration worsens the problem as fragments circulate through the lubrication system.

• Metallic rattling or slapping noise from the front of the engine during the first 5–20 seconds after a cold start
• Rattle becoming continuous at higher mileage regardless of engine temperature
• Rough idle or misfires caused by camshaft timing error if chain has jumped a tooth
• Check engine light with VVT or camshaft position sensor codes (P0340, P0345)

1. 1

   Start the engine from cold and immediately listen at the front of the engine for a metallic rattle or slap in the first 10–15 seconds.

2. 2

   Inspect oil for plastic fragments from guide deterioration.

3. 3

   Check camshaft timing marks align correctly at TDC — misalignment indicates a jumped chain.

4. 4

   If a workshop inspection is possible: Check for timing chain stretch using a dial indicator on the crankshaft pulley with the front cover removed (workshop procedure).

Parts involved: Timing chain.

$2,200 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 chain, tensioners, or guides ever been replaced?”
• “Does the engine rattle on cold starts, even briefly?”
• “What is the current odometer reading, and has the engine had regular oil changes every 5,000 km?”

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.