Mercedes-Benz GLA: M270/M274 Timing Chain Guide Wear - Cold Rattle

The M270 and M274 petrol engines in the GLA200 and GLA250 share the same plastic timing chain guide and tensioner design flaw as the W176 platform. Cold-start rattle is the definitive symptom and can progress to chain stretch and eventual timing jump if ignored. NZ-market vehicles are often subject to longer service intervals than recommended, accelerating guide deterioration. The repair requires front engine cover removal and typically involves replacing the full chain kit including guides, tensioner, and the chain itself. Parts cost alone runs NZD 600-1000 with significant labour on top. Chain failure mid-drive causes immediate catastrophic engine damage.

• Loud rattling or ticking on cold engine start from front of engine
• Noise settles within 20-30 seconds as oil pressure builds
• MIL with P0016 or P0017 camshaft timing correlation codes
• Rough idle when cold
• Engine runs rough or loses power in advanced cases

1. 1

   Perform a cold start with bonnet open and listen carefully for chain rattle before oil pressure builds.

2. 2

   Scan for fault codes.

3. 3

   Review oil service records - intervals longer than 10,000km on standard oil significantly increase risk.

4. 4

   Check for any evidence of chain rattle noise noted in previous workshop invoices.

5. 5

   An independent pre-purchase inspection with cold-start listening procedure is strongly advisable.

Parts involved: Timing chain.

$1,800 to $4,000 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 system been inspected or the guides replaced?”
• “What are the oil change intervals and what oil specification was used?”
• “Has there been any cold-start rattling noise from the engine?”
• “Are there stored or current fault codes for camshaft timing?”

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.