KNOWN FAULTS · Mercedes-Benz

Mercedes-Benz Clase S (W221) S 350 / 500 common problems.

2005–2013 · Petrol

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

3 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.

M272 / M273 balance shaft sprocketValve timing

Engine / equipment: M272 V6 (280, 300, 350) and M273 V8 (450, 500, 550) in the C, E, CLK, CLS, SLK, ML, GL, R, S and CL
Period mentioned: 2004–2008 (engines below serial number 2729..30 468993)
Symptoms: Engine light with P0016 and P0017 (1200 and 1208 on Mercedes diagnostics), rattle on start-up, hesitation, misfires and, in severe cases, stalling.
Possible cause described: Balance shaft sprocket (M272) or timing idler gear (M273) made from metal that is too soft: the teeth wear, the chain goes slack and the timing slips. Mercedes changed the material in mid-2008.
Check for the garage: Compare the engine serial number with the 2729..30 468993 cut-off, read cam correlation codes and, if in doubt, inspect the sprocket with a borescope. First rule out the cam adjuster magnet (a cheap fault).
Cost cited in the source: Engine-out repair: over €3,700 (converted from dollars)A rough figure from the original database, not an up-to-date quote.

Applies if: Only if fitted with air suspension.

AIRMATIC leaks and compressorSuspension

Engine / equipment: AIRMATIC air suspension: E-Class W211, W212 and W213, S W220 to W223, CLS, CL, ML W164, GL, GLE and GLS
Period mentioned: 2002–2026
Symptoms: One corner sags overnight, suspension fault warning, the compressor runs a lot or a compressor overheated message appears; eventually the car sits low and rides hard.
Possible cause described: The air bellows on the struts leak with age, often at the upper crimp rings, and the compressor overworks until it burns out. The valve block and lines also leak, and the compressor relay (in the rear SAM on W221, W222 and W213) and ride height sensors fail.
Check for the garage: Spray soapy water on bellows, lines and valve block; read each corner's data with Xentry; check the compressor fuse and relay. Do not replace the compressor without fixing the leak first, or the new one will fail soon.
Cost cited in the source: Compressor: approx. €600–1,200 at an independent garage (converted from Canadian dollars); bellows: depends on the cornerA rough figure from the original database, not an up-to-date quote.

Mileage cited in the database: 95,000–115,000 km. This is not a maintenance interval and does not predict a failure.