Models · Mercedes-Benz
Mercedes-Benz SLK and SLC R172 buying guide
The third-generation SLK arrived in 2011 with four- and six-cylinder petrol engines, a diesel for the first time, and the folding hard top, with the SLK55 AMG at the top of the range. Reported problems are few on the whole.
The versions
- SLK200 and SLK250: 1.8 litre turbocharged four-cylinder petrol, 184bhp and 204bhp
- SLK350: 3.5 litre V6 petrol, 306bhp
- SLK250 CDI: 2.15 litre four-cylinder diesel, 204bhp, the first diesel SLK
- SLK55 AMG: 5.5 litre naturally aspirated V8, 421hp
- Seven-speed 7G-Tronic Plus automatic; six-speed manual on the SLK200 only
What to check on a R172 SLK or SLC
3 model-specific things to look at when you view one. They're a starting point, not the full inspection.
Roof and boot divider latches
What to look for: Operate the roof fully open and closed at least twice. Watch that the divider between the roof storage area and the boot locks into place, because the roof won't lower until it does. A roof that hesitates, stops or won't move is the thing to note.
Why it matters: Latches on the roof and boot divider can fail to seat properly in their catch, which can jam the roof open or closed. Many owners report problems with the folding hard top, so a roof that cycles cleanly several times is a good sign.
Rear axle, subframe and brake line corrosion
What to look for: From underneath, with a torch, look at the rear subframe, the rear axle parts and the metal brake lines running along the underside for flaking or heavy rust.
Why it matters: Corrosion of the rear subframe on older cars can cause an MOT failure, and rust on the rear axle and brake lines is becoming common as these cars age. Brake lines are a straightforward replacement; heavy subframe corrosion is a bigger job.
Water getting in
What to look for: Check the boot floor and the footwells for damp or water, and look at the seals around the windscreen and the front pillars. Test the electric windows and door locks on both sides.
Why it matters: Water can get in through the A-pillar and windscreen seals and affect the door control modules, and the folding roof mechanism can let water into the boot. Hardened, squeaking roof seals can be helped with the right grease.
Also in the full guide
- Automatic gearbox that stops at fifth
- The cold start, test drive and paperwork checks for the exact version you're viewing
The full guide to the R172 SLK or SLC
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.