Mercedes-Benz S-Klasse W221
Weaknesses, engine ratings and buying advice
500–630 PS
5.5L V12 BiTurbo Benzin
S 600 W220 — V12 in the First BiTurbo S-Class
Fun to Drive!525–585 PS
5.5L V8 BiTurbo Benzin
11 weaknesses
Stay Away!Generations
Engine Overview
The Mercedes-Benz S-Klasse W221 is available with 10 engine variants — from 120 to 630 hp. 1 variants had engine changes — the model year is crucial.
The Mercedes-Benz S 250 CDI (Diesel, 204 PS) has the OM651DE22 (2.1L Diesel) — rated: "Stay Away!", 6 known weaknesses.
The Mercedes-Benz S 320 CDI (Diesel, 235 PS) has the OM642 (3.0L V6 Diesel) — rated: "Stay Away!", 7 known weaknesses.
The Mercedes-Benz S 350 CDI (Diesel, 258 PS) has the OM642 (3.0L V6 Diesel) — rated: "Stay Away!", 7 known weaknesses.
The Mercedes-Benz S 420 CDI (Diesel, 320 PS) has the OM629 (4.0L V8 CDI) — rated: "Stay Away!", 6 known weaknesses.
The Mercedes-Benz AMG S 63 (Benziner, 525–544 PS) comes with 2 different engines: M156 (2006–2010, Stay Away!) und M157 (2010–2013, Stay Away!). Pay attention to the model year for the AMG S 63!
The Mercedes-Benz S 350 (Benziner, 272 PS) has the M272 (3.0-3.5L V6) — rated: "Stay Away!", 6 known weaknesses.
The Mercedes-Benz S 450 (Benziner, 340 PS) has the M273 (5.0-5.5L V8) — rated: "Stay Away!", 9 known weaknesses.
The Mercedes-Benz S 500 (Benziner, 388 PS) has the M273 (5.0-5.5L V8) — rated: "Stay Away!", 9 known weaknesses.
The Mercedes-Benz S 600 (Benziner, 517 PS) has the M275 (5.5L V12 BiTurbo) — rated: "Stay Away!", 9 known weaknesses.
The Mercedes-Benz S 65 AMG (Benziner, 612 PS) has the M275 (5.5L V12 BiTurbo) — rated: "Stay Away!", 9 known weaknesses.
Vehicle Weaknesses
| Weakness | Cost | |
|---|---|---|
| Airmatic air struts leaking The air struts of the W221 wear over time. Between 200,000 and 300,000 km, all four struts typically need replacement. Symptoms: Vehicle drops or sits lopsided, Airmatic fault message, compressor runs continuously from 220,000 km | High | |
| Pressure reservoir tank corroded (rear axle) The Airmatic pressure reservoir tanks at the rear axle can corrode. Removal requires disassembly of the rear axle. Symptoms: Airmatic fault message, pressure loss in system, vehicle drops after standing from 180,000 km | High | |
| Airmatic air spring bags leaking — vehicle sits lopsided Air spring bags (usually rear) become leaky and lose pressure gradually. The vehicle then sits 3–4 cm lower on one side. Fault code 5285 (fill process too long) appears. Repair is only possible by replacement. Symptoms: Vehicle sits lopsided, warning 'vehicle too low' in instrument cluster, compressor runs frequently, yellow warning light from 120,000 km | High |
Top Reported Issues
Alternatives
Known Problems and Issues
A total of 70 weaknesses have been documented for the Mercedes-Benz S-Klasse W221 (2005–2013) — 64 engine-related and 6 vehicle-related. 8 problem engines: OM651DE22 (2.1L Diesel), M272 (3.0-3.5L V6), M273 (5.0-5.5L V8), OM642 (3.0L V6 Diesel), M156 (6.2L V8 AMG), M157 (5.5L V8 BiTurbo), M275 (5.5L V12 BiTurbo), OM629 (4.0L V8 CDI). Typical issues affect Suspension, Electronics.
S-Klasse (OM642, 2006–2013) — Stay Away!: Oil Cooler Gaskets Leaking — Oil and Coolant Loss, Swirl Flap Linkage Breaks — Plastic Joint Fails, Injector Seal Leaking — Soot Deposits and Diesel in Oil. Power: 235 PS.
S-Klasse (OM629, 2006–2009) — Stay Away!: Cylinder head warped -- coolant loss, NAG2 transmission at torque limit, Oil Cooler Leak in V-Section. Power: 320 PS.
S-Klasse (OM642, 2010–2013) — Stay Away!: Oil Cooler Gaskets Leaking — Oil and Coolant Loss, Swirl Flap Linkage Breaks — Plastic Joint Fails, Injector Seal Leaking — Soot Deposits and Diesel in Oil. Power: 252–258 PS.
S-Klasse (OM651DE22, 2011–2013) — Stay Away!: Chain Tensioner Seal Leaking — Recall, Timing Chain Stretch (Simplex Chain), Piezo Injector Faults. Power: 204 PS.
S-Klasse (M272, 2005–2013) — Stay Away!: Balance Shaft Sprocket Wears Prematurely, Timing Chain Stretches and Damages Timing, Camshaft Adjuster Leaks — Wiring Harness Contaminated. Power: 272–279 PS.
S-Klasse (M273, 2005–2013) — Stay Away!: Balance shaft sprocket — same weakness as M272, Camshaft Adjuster Leaking — Oil in Wiring Harness, Valve cover gaskets leaking on both sides. Power: 387 PS.
S-Klasse (M275, 2005–2013) — Stay Away!: Ignition module bank failure (two banks at ~€1,400 each), Turbocharger wear and wastegate wear, ABC hydraulic lines and engine mounts — double defect. Power: 517 PS.
S-Klasse (M273, 2006–2010) — Stay Away!: Balance shaft sprocket — same weakness as M272, Camshaft Adjuster Leaking — Oil in Wiring Harness, Valve cover gaskets leaking on both sides. Power: 340 PS.
S-Klasse (M156, 2006–2010) — Stay Away!: Head Bolt Corrosion — Coolant in Combustion Chamber, Camshaft Wear — Cold-Start Lubrication Deficit, Camshaft Adjuster — Locking Plate Wears Out. Power: 525 PS.
S-Klasse (M275, 2006–2013) — Stay Away!: Ignition module bank failure (two banks at ~€1,400 each), Turbocharger wear and wastegate wear, ABC hydraulic lines and engine mounts — double defect. Power: 612 PS.
S-Klasse (M157, 2010–2013) — Stay Away!: Timing Chain Stretch — M157 BiTurbo V8, Oil Consumption from Piston Ring Wear, High-Pressure Fuel Pump Fails — No Fuel Pressure. Power: 544 PS.
What to watch out for with the Mercedes-Benz S-Klasse? See the detailed listing of all engine and vehicle weaknesses in the sections above.
Frequently Asked Questions
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Last updated: February 2026 · All information without guarantee