Models · Mercedes-Benz
Mercedes-Benz SLK R171 buying guide
The second-generation SLK went on sale in 2004 with four-cylinder Kompressor, V6 and AMG V8 engines, all driving the rear wheels, and a folding hard top. A facelift in April 2008 brought more power. Its roof is one of the most reliable of its type if used regularly.
The versions
- SLK200 Kompressor: 1.8 litre four-cylinder, 163bhp, 184bhp from the April 2008 facelift
- SLK280 (later SLK300): 3.0 litre V6, 231bhp, from June 2005
- SLK350: 3.5 litre V6, 272bhp, 305bhp after the facelift
- SLK55 AMG: 5.4 litre V8, covered separately
- Six-speed manual standard on the SLK200 and SLK350, with an optional automatic; no diesel
What to check on a R171 SLK
3 model-specific things to look at when you view one. They're a starting point, not the full inspection.
Roof speed and motors
What to look for: Lower and raise the roof several times. It should move steadily and complete the cycle every time. Slower than usual movement, stalling, or a roof that won't complete its cycle are the things to note. Ask how often the roof has been used.
Why it matters: The folding hard top is reliable if it's operated regularly, but the electric motors can seize if it's left in one position for too long. Slow retraction usually points to a faulty hydraulic pump. A roof that cycles cleanly several times is a good sign.
Water in the boot
What to look for: Lift the boot floor and look in the spare wheel well for standing water, damp carpet or tide marks. Feel the boot carpets at the edges.
Why it matters: The boot seals are prone to failure, which lets water collect in the spare wheel well and soak the carpets. It's a relatively simple fix if caught early.
Rear axle and brake line corrosion
What to look for: From underneath, with a torch, look at the rear axle parts and the metal brake lines running along the underside for flaking or heavy rust.
Why it matters: Corrosion on the rear axle and brake lines is a known issue as these cars age. Brake lines are a straightforward replacement, and a clean underside is a sign of a car that's been looked after.
Also in the full guide
- The fuel shut-off recall
- The cold start, test drive and paperwork checks for the exact version you're viewing
The full guide to the R171 SLK
The CrankSight guide walks you round the car on your phone at the viewing, with every check for the exact version you're looking at: what to look for, where to find it, and what anything you find is likely to cost. As you go it builds an assessment of that car, and if you view more than one, it lines them up side by side.
£29 for the model, used on as many cars as you like, delivered within 72 hours or your money back.
Other generations
General points for the model, last checked October 2026. Every car is different, so treat this as a guide to what to look at, not a verdict on any car. CrankSight is independent and has no connection with Mercedes-Benz.