Models · Mercedes-Benz
Mercedes-Benz SLK55 AMG R171 buying guide
The R171 SLK55 AMG put the naturally aspirated M113 5.4 litre V8 into the compact SLK roadster, with an automatic gearbox only. A 2008 revision brought faster gearbox software, and a hardtop Black Series coupé followed in 2006.
The versions
- M113 5.4 litre naturally aspirated V8, 355 to 360hp and 376lb ft
- Seven-speed automatic only, with faster shift software from 2008
- Black Series (2006): fixed-roof coupé, 400hp
- Folding hard top, rear-wheel drive
What to check on a R171 SLK55
3 model-specific things to look at when you view one. They're a starting point, not the full inspection.
The folding roof
What to look for: Operate the roof fully open and closed several times. Watch that the divider between the roof storage area and the boot locks into place, and that the roof completes its cycle every time without slowing or stalling. Check the boot and cabin for damp.
Why it matters: Latches between the roof storage compartment and the boot can jam the roof open or closed, and the electric motors can seize if the roof is left in one position for long periods. Some owners have also reported water getting in. A roof that cycles cleanly several times is a good sign.
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 the known underside issue on the SLK55. Brake lines are a straightforward replacement, and a clean underside is a sign of a car that's been looked after.
Electrical faults after a battery change
What to look for: Ask whether the battery has been changed recently or the car jump-started. Test every electrical item: windows, roof, seats, air conditioning, Airscarf if fitted, and the instrument displays, and watch for warning lights.
Why it matters: A variety of electrical faults can appear on the SLK55 after a battery change or jump start, and the optional Airscarf neck heater can be temperamental. A specialist diagnostic scan is the way to check.
Also in the full guide
- Airbag and fuel shut-off recalls
- The cold start, test drive and paperwork checks for the exact version you're viewing
The full guide to the R171 SLK55
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.