2008 MERCEDES-BENZ S-Class M273 V8/OM642 V6 Diesel (W221)
W221 / Sedan / Global / primary markets include Europe, North America, Asia
M273 V8OM642 V6 DieselM156 V8 AMGM278 V8 Biturbo (introduced late 2008 in some markets)Exakter Jahres-/Varianten-DatensatzGold
Engine identity
Oils and fluids
Service and parts data
Common and chronic problems
- Airmatic suspension compressor failure
- Balance shaft issues in early M273 engines
- Electrical gremlins with COMAND system
First checks
- Inspect Airmatic suspension function and compressor
- Check oil consumption on M273 and M156 engines
- Verify timing chain tensioner condition
Vor dem Teiletausch
- Save fault codes and freeze-frame data before clearing anything.
- Check engine oil, coolant and transmission fluid using the correct temperature and service procedure.
- Verify power, ground, connectors, hoses, leaks and live data before replacing expensive parts.
Important notes
- Market variations affect engine availability; diesel engines mainly in Europe and select global markets.
- M278 twin-turbo V8 introduction started around late 2008 in EU and USA, mostly on S500 models.
- Oil capacity depends on engine variant and should be confirmed by engine code.