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Mercedes-Benz · Convertible / Roadster · 2004–2011

Mercedes-Benz SLK R171

Weaknesses, engine ratings and buying advice

★★★★★
1.7 / 5.0 · Based on 3 engine variants
Most Fun Engine

272–517 PS

4.3-5.4L V8 Benzin

400 hp NA Extreme — Black Series in a Roadster

Legendary!
Problem Engine

143–204 PS

1.8L Kompressor Benzin

6 weaknesses

Stay Away!

Generations

Engine Overview

The Mercedes-Benz SLK R171 is available with 4 engine variants — from 143 to 517 hp. 3 variants had engine changes — the model year is crucial.

SLK 200 Kompressor · Benziner· 163–184 PS Engine Change
2004 2008
Stay Away! 6 weaknesses
2008 2011
Stay Away! 6 weaknesses
SLK 280 · Benziner· 231 PS
2005 2011
Stay Away! 6 weaknesses
SLK 350 · Benziner· 272–306 PS Engine Change
2004 2008
Stay Away! 6 weaknesses
2008 2011
Stay Away! 6 weaknesses
SLK 55 AMG · Benziner· 360–400 PS Engine Change
2004 2008
Be Careful 10 weaknesses
Show all weaknesses →
2008 2011
Be Careful 10 weaknesses
Show all weaknesses →
2008 2011
Be Careful 10 weaknesses
Show all weaknesses →

The Mercedes-Benz SLK 200 Kompressor (Benziner, 163–184 PS) comes with 2 different engines: M271 (2004–2008, Stay Away!) und M271 (2008–2011, Stay Away!). Pay attention to the model year for the SLK 200 Kompressor!

The Mercedes-Benz SLK 280 (Benziner, 231 PS) has the M272 (3.0-3.5L V6) — rated: "Stay Away!", 6 known weaknesses.

The Mercedes-Benz SLK 350 (Benziner, 272–306 PS) comes with 2 different engines: M272 (2004–2008, Stay Away!) und M272 (2008–2011, Stay Away!). Pay attention to the model year for the SLK 350!

The Mercedes-Benz SLK 55 AMG (Benziner, 360–400 PS) comes with 3 different engines: M113 (2004–2008, Be Careful) und M113 (2008–2011, Be Careful) und M113 (2008–2011, Be Careful). Pay attention to the model year for the SLK 55 AMG!

Vehicle Weaknesses

WeaknessCost
✖Rear axle completely corroded through

Rear axles on older R171 corrode completely through. Mercedes acknowledges this as a known problem and replaces the entire rear axle as a goodwill gesture. Immediate complaint is recommended when rust is found.

Symptoms: Visible rust on rear axle cross-member, creaking noises from rear axle
from 100,000 km
Ad rear axle SLK R171Achsträger SLK 171Hinterachsträger Mercedes SLK
 High
NHTSA Owner Complaints
Average
114 complaints · 2004–2011
Airbags
44 ⚠ 1
Powertrain
22
Electrical
10
Other
9 ⚠ 1
Engine & Cooling
8 ⚠ 1

Top Reported Issues

⚠ Airbags (44 complaints)
⚠ Powertrain (22 complaints)
⚠ Electrical (10 complaints)
Source: NHTSA (nhtsa.gov) · 2026-03

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Known Problems and Issues

A total of 31 weaknesses have been documented for the Mercedes-Benz SLK R171 (2004–2011) — 22 engine-related and 9 vehicle-related. 2 problem engines: M271 (1.8L Kompressor), M272 (3.0-3.5L V6). Typical issues affect Rust, Body, Electronics, Suspension.

SLK (M113, 2004–2008) — Be Careful: Vibration Damper/Pulley — Rubber Hardens, Rear Crankshaft Seal Leaking, Engine Mounts Worn Prematurely. Power: 360 PS.

SLK (M271, 2004–2008) — Stay Away!: Timing Chain Stretches Prematurely, Camshaft Adjuster Leaks — Oil in Wiring Harness, Camshaft Adjuster Leaks Oil into Connector. Power: 163 PS.

SLK (M272, 2004–2008) — Stay Away!: Balance Shaft Sprocket Wears Prematurely, Timing Chain Stretches and Damages Timing, Camshaft Adjuster Leaks — Wiring Harness Contaminated. Power: 272 PS.

SLK (M272, 2005–2011) — Stay Away!: Balance Shaft Sprocket Wears Prematurely, Timing Chain Stretches and Damages Timing, Camshaft Adjuster Leaks — Wiring Harness Contaminated. Power: 231 PS.

SLK (M113, 2008–2011) — Be Careful: Vibration Damper/Pulley — Rubber Hardens, Rear Crankshaft Seal Leaking, Engine Mounts Worn Prematurely. Power: 400 PS.

SLK (M113, 2008–2011) — Be Careful: Vibration Damper/Pulley — Rubber Hardens, Rear Crankshaft Seal Leaking, Engine Mounts Worn Prematurely. Power: 387 PS.

SLK (M271, 2008–2011) — Stay Away!: Timing Chain Stretches Prematurely, Camshaft Adjuster Leaks — Oil in Wiring Harness, Camshaft Adjuster Leaks Oil into Connector. Power: 184 PS.

SLK (M272, 2008–2011) — Stay Away!: Balance Shaft Sprocket Wears Prematurely, Timing Chain Stretches and Damages Timing, Camshaft Adjuster Leaks — Wiring Harness Contaminated. Power: 305–306 PS.

What to watch out for with the Mercedes-Benz SLK? See the detailed listing of all engine and vehicle weaknesses in the sections above.

Frequently Asked Questions

What problems and weaknesses does the Mercedes-Benz SLK R171 have? +
The Mercedes-Benz SLK R171 has 22 known engine weaknesses and 9 vehicle weaknesses.
What should I look for when buying a used Mercedes-Benz SLK R171? +
faq.watch_a_avoid
Which engine is recommended? +
Be careful: M113 (4.3-5.4L V8). No engine is rated 'Good Choice'. The most fun to drive is the M113 (4.3-5.4L V8). Problem engine: M271 (1.8L Kompressor) — stay away!
Which Mercedes-Benz SLK R171 engine is the most fun? +
The {code} ({displacement}) offers the most driving fun in the Mercedes-Benz SLK R171 — rated: "Legendary!". {description} Strongest M113 variant in the SLK: revised inlet ports, sharpened camshafts. Above 5,000 rpm the sound becomes metallic-sharp, almost like a racing engine. Under 1,500 kg with 400 naturally aspirated hp — performance at GT3 level for a fraction of the price. Brake upgrade recommended for track days; standard brakes adequate for road use.
Is the Mercedes-Benz SLK R171 worth buying used? +
Caution is advised with the Mercedes-Benz SLK R171 — 2 of 3 engine variants are rated 'Stay Away!'. The engine choice is crucial.
What horsepower variants are available for the Mercedes-Benz SLK R171? +
The Mercedes-Benz SLK R171 is available with engine variants from 143 to 517 hp. Petrol: M113 (4.3-5.4L V8), M271 (1.8L Kompressor), M272 (3.0-3.5L V6).

Last updated: February 2026 · All information without guarantee