Honda N-Box: S07A Timing Chain Tensioner Wear at Cold Start

The S07A 660cc turbocharged engine uses a hydraulic timing chain tensioner that loses oil-pressure retention after extended cold soaks. On a fully cold start the tensioner fails to take up chain slack immediately, producing a metallic rattle or ticking from the timing cover for 2-5 seconds until oil pressure builds. Repeated cold-start events accelerate chain stretch and guide wear. Prolonged neglect allows chain slack to accumulate, risking valve-timing displacement, camshaft code faults, or catastrophic chain failure at high revs. The issue is worsened by extended oil-change intervals or low-viscosity oil use in a high-mileage engine.

• Metallic rattle or ticking from engine top end on cold start
• Noise clears within 2-5 seconds once oil pressure builds
• Rattle absent on warm re-start
• MIL for VTC or camshaft timing codes in advanced cases
• Visible timing chain tensioner oil seepage

1. 1

   Start the engine fully cold (overnight soak preferred) and listen for metallic rattle from the timing cover on the front of the engine.

2. 2

   Time how long the noise persists.

3. 3

   Pull any stored fault codes for VTC or camshaft timing.

4. 4

   Check oil level and viscosity in service records.

Parts involved: Timing chain.

$850 to $2,200 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.

• “Does the engine make any rattling sound on a cold start?”
• “Has the timing chain tensioner ever been inspected or replaced?”
• “What oil change interval has been followed, and what viscosity is used?”
• “Has a check engine light appeared for any engine timing codes?”

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.