Mercedes-Benz R-Klasse W251
Weaknesses, engine ratings and buying advice
457–525 PS
6.2L V8 AMG Benzin
V8 in a Van — the Most Absurd AMG of All Time
Fun to Drive!457–525 PS
6.2L V8 AMG Benzin
10 weaknesses
Stay Away!Engine Overview
The Mercedes-Benz R-Klasse W251 is available with 7 engine variants — from 190 to 525 hp. 3 variants had engine changes — the model year is crucial.
The Mercedes-Benz R 280 CDI (Diesel, 190 PS) has the OM642 (3.0L V6 Diesel) — rated: "Stay Away!", 7 known weaknesses.
The Mercedes-Benz R 320 CDI (Diesel, 211–224 PS) comes with 2 different engines: OM642 (2005–2009, Stay Away!) und OM642 (2005–2009, Stay Away!). Pay attention to the model year for the R 320 CDI!
The Mercedes-Benz R 350 CDI (Diesel, 265 PS) has the OM642 (3.0L V6 Diesel) — rated: "Stay Away!", 7 known weaknesses.
The Mercedes-Benz R 280 (Benziner, 231 PS) has the M272 (3.0-3.5L V6) — rated: "Stay Away!", 6 known weaknesses.
The Mercedes-Benz R 350 (Benziner, 272–306 PS) comes with 2 different engines: M272 (2006–2012, Stay Away!) und M276 (2011–2014, Be Careful). Pay attention to the model year for the R 350!
The Mercedes-Benz R 500 (Benziner, 306–388 PS) comes with 2 different engines: M273 (2005–2007, Stay Away!) und M273 (2007–2014, Stay Away!). Pay attention to the model year for the R 500!
The Mercedes-Benz R 63 AMG (Benziner, 510 PS) has the M156 (6.2L V8 AMG) — rated: "Stay Away!", 10 known weaknesses.
Vehicle Weaknesses
| Weakness | Cost | |
|---|---|---|
| Airmatic Air Spring Bellows Leaking The Airmatic air spring bellows develop leaks and cause the vehicle to sink. The vehicle sits lower on one side when parked. Arnott replacement bellows approximately €200; workshop costs up to €1,900. Symptoms: Vehicle sits low on one side, Airmatic fault message, compressor runs continuously from 100,000 km | Medium | |
| Airmatic Compressor Worn The Airmatic air suspension compressor wears at high mileage, particularly if the air spring bellows were already leaking and the compressor had to run continuously. Replacement compressor €400–700; expensive to fit. Symptoms: Compressor runs continuously, loud operating noises from the compressor, vehicle ride height dropping from 150,000 km | High |
Alternatives
Known Problems and Issues
A total of 49 weaknesses have been documented for the Mercedes-Benz R-Klasse W251 (2005–2014) — 42 engine-related and 7 vehicle-related. 4 problem engines: M272 (3.0-3.5L V6), M273 (5.0-5.5L V8), OM642 (3.0L V6 Diesel), M156 (6.2L V8 AMG). Typical issues affect Suspension, Gearbox, Rust, Electronics.
R-Klasse (OM642, 2005–2009) — 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: 211 PS.
R-Klasse (OM642, 2005–2009) — 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: 224 PS.
R-Klasse (OM642, 2007–2014) — 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: 190 PS.
R-Klasse (OM642, 2010–2014) — 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: 265 PS.
R-Klasse (M273, 2005–2007) — Stay Away!: Balance shaft sprocket — same weakness as M272, Camshaft Adjuster Leaking — Oil in Wiring Harness, Valve cover gaskets leaking on both sides. Power: 306 PS.
R-Klasse (M272, 2006–2012) — Stay Away!: Balance Shaft Sprocket Wears Prematurely, Timing Chain Stretches and Damages Timing, Camshaft Adjuster Leaks — Wiring Harness Contaminated. Power: 272 PS.
R-Klasse (M156, 2006–2014) — Stay Away!: Head Bolt Corrosion — Coolant in Combustion Chamber, Camshaft Wear — Cold-Start Lubrication Deficit, Camshaft Adjuster — Locking Plate Wears Out. Power: 510 PS.
R-Klasse (M272, 2007–2014) — Stay Away!: Balance Shaft Sprocket Wears Prematurely, Timing Chain Stretches and Damages Timing, Camshaft Adjuster Leaks — Wiring Harness Contaminated. Power: 231 PS.
R-Klasse (M273, 2007–2014) — 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.
R-Klasse (M276, 2011–2014) — Be Careful: Oil cooler leaking in the V-block, Camshaft adjuster leaking — wiring harness contaminated, Piston slap (early 3.5L variants). Power: 306 PS.
What to watch out for with the Mercedes-Benz R-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