C63 AMG W204 inspection checklist

Look for: Owner/reviewer-reported: rear subframe corrosion, worse in colder climates. In Australia this matters most for cars that have lived in the snow country or near the sea.

Look for: Early M156 engines (reported on 2008-2011 builds) can snap cylinder head bolts, which leads to head gasket failure and engine damage. UK and Australian guides describe it as rare, and one says it is more common in the USA than Europe. Mercedes is reported to have replaced engines under warranty. An owner forum claim that 2012 and later engines have revised parts and avoid the fault is a single unverified post, so do not rely on year alone. Signs: coolant loss, white smoke, overheating, misfire.

Look for: Owner/reviewer-reported: worn cam lifters wear the camshaft lobes, causing a ticking or rough running; the cure is a top-end rebuild with new cams and lifters. A used-car review for Australian buyers says parts may need replacing by about 150,000 km and that 5,000 km oil changes help. UK guides call the fault rare.

Look for: Injectors can stick open and flood a cylinder with fuel. In the worst case hydraulic lock bends or breaks a conrod. Two guides mention it; one suggests replacing injectors ahead of failure if the budget allows.

Look for: Owner/reviewer-reported: a rattle for a second or two at cold start from worn cam adjusters (phasers). A single Australian used review gives the dealer price quoted; we could not confirm it elsewhere. Ignore a cold-start rattle and the camshaft and chain wear follow.

Look for: Cracked or leaking intake manifolds cause a rough idle (a warning sign cited in UK and Australian guides). Valve cover oil leaks are also reported by owners. Aftermarket kits exist for both.

Look for: A UK buying guide says the Series II front bumper restricts airflow to the radiators, so the gearbox can overheat under hard driving. Its suggested fix is the Black Series cooling upgrade with a Black Series bumper, and it says the parts could be expensive. A second UK guide calls the transmission extremely reliable and reports no MCT faults. Single-source on the overheating.

Look for: The car's weight and power wear front pads, discs and rear tyres quickly. Australian used-car review says AMG brakes are very expensive to maintain and many owners fit aftermarket systems. Performance Pack and 507 cars have larger or composite front discs that cost more again.

Look for: Official: a 2010 recall covered fluid loss at the power steering pump high-pressure line connection on W204/W212/C207 cars (see Recalls). Owner-reported: a power steering hose can chafe through the sump.

Look for: Australian owners report ads with made-up power figures (a suspicious '380kW' claim on a pack car and a 'Black Series' that was not one). The pack is a factory option on the standard C63 with 358kW and the engine and brake changes listed above.