KNOWN FAULTS · Mercedes-Benz

Mercedes-Benz Clase C (W204) C 63 AMG (M156, 6.2 V8) common problems.

2007–2014 · Petrol

Sources are not verified in real time and no entry confirms that your car is affected.

2 known faults with sources

Applies if: Only if fitted with 7G-Tronic. Confirm the gearbox type.

7G-Tronic conductor plateGearbox

Engine / equipment: 7G-Tronic automatic gearbox (722.9) in the C, E, S-Class, ML, GL, SLK, Sprinter…
Period mentioned: 2004 onwards (more failures in 2004–2008)
Symptoms: Gearbox stuck in 2nd or 3rd (limp mode), harsh shifts, delay engaging D or R, gearbox warning often without an engine light; turning off and restarting clears it for a while.
Possible cause described: The conductor plate (the control unit with built-in speed sensors) fails from heat and vibration. Oil leaks through the 13-pin connector are also common.
Check for the garage: Diagnose with Xentry/STAR to see the sub-codes (a basic reader only shows P0700). Check for oil in the gearbox connector.
Cost cited in the source: Approx. €1,400–2,800 (estimate)A rough figure from the original database, not an up-to-date quote.

AMG 6.2 (M156) head bolts and camshaftsEngine (cylinder head / valvetrain)

Engine / equipment: M156 6.2 V8 AMG (C 63 W204, E 63 W211 and W212 until 2011, CLK 63, CLS 63, ML 63, S 63 and CL 63 until 2010, SL 63)
Period mentioned: 2006–2015
Symptoms: Coolant loss, coolant in the oil or white smoke (broken head bolts); rattle or ticking on start-up (camshaft and lifter wear).
Possible cause described: Cylinder head bolts that break on engines up to 2012 (Mercedes bulletin from 2011) and nodular cast-iron camshafts that wear together with the lifters, mainly on the intake side (bulletin from 2009).
Check for the garage: Overnight cooling system pressure test, oil analysis and camshaft inspection with a borescope.
Cost cited in the source: Major engine repair (several thousand euros)A rough figure from the original database, not an up-to-date quote.