Mercedes-Benz A-Class: M270 1.6/2.0 turbo timing chain guide wear, cold rattle (W176)

The plastic timing chain guides and tensioner on the M270 1.6T and M274 2.0T engines are prone to premature wear and cracking. On cold start a distinct metallic rattling from the front of the engine is the primary symptom. If neglected the chain can skip timing, causing catastrophic engine damage including bent valves and piston contact. Mercedes issued a service campaign but did not fully recall affected vehicles. The fault is exacerbated by infrequent oil changes or use of incorrect viscosity oil. Many NZ examples have exceeded the recommended update interval without the repair being completed.

• Metallic rattling or clattering on cold engine start from front of engine
• Noise disappears after 10-30 seconds as oil pressure builds
• Check Engine Light with camshaft timing codes P0016 or P0017
• Rough idle on cold start
• Engine performance loss or misfires in severe cases

1. 1

   Start the engine cold and listen for rattling from the front-left of the engine bay before oil pressure builds.

2. 2

   Scan for active or stored DTCs relating to camshaft timing correlation.

3. 3

   Review oil service history to verify correct MB 229.5 or 229.51 specification and intervals under 10,000km.

4. 4

   Inspect oil filler cap for sludge indicating poor maintenance history.

Parts involved: Timing chain, Turbocharger.

$1,800 to $3,800 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 chain guides ever been replaced or inspected?”
• “Can you provide full service history showing oil change intervals and specification used?”
• “Has the vehicle ever exhibited a cold-start engine rattle?”
• “Are there any stored or current fault codes for camshaft timing correlation?”

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.