Models · Mercedes-Benz
Mercedes-Benz S-Class W221 buying guide
The fifth S-Class, built from 2005 and sold in the UK from 2006 to 2013, with a facelift in 2009. Diesels are the most common choice, and it's mechanically sound overall when it's been maintained properly.
The versions
- Diesel: S320 CDI V6 (232bhp) before the facelift, S350 CDI (268bhp) after it; the diesels are the easiest to find
- Petrol: S280 3.0 V6 and larger V6 and V8 engines
- Standard and long-wheelbase saloon
- Seven-speed automatic, with gearbox oil changes due every 40,000 miles
- The S400 Hybrid is not covered here; the S63 and S65 AMG are covered separately
What to check on a W221 S-Class
3 model-specific things to look at when you view one. They're a starting point, not the full inspection.
Air suspension ride height
What to look for: When you arrive, check the car is sitting level on all four corners and hasn't sunk overnight. On the drive, take a few corners at moderate speed and feel whether the car stays level or leans more than you'd expect.
Why it matters: If the car doesn't stay level in corners, the suspension pump may need replacing. A car that sits evenly and corners flat is what you want to see.
Rattling at idle on the diesels
What to look for: On a diesel, start the engine from cold with the bonnet up and listen at idle. Note any persistent rattling from the engine, and ask whether the timing chain has ever been replaced.
Why it matters: Excessive rattling at idle can mean a stretched timing chain, which needs attention before it gets worse, as a failure can do serious damage to the engine. Engine failures are isolated, and a quiet idle is a good sign.
Test every electrical feature
What to look for: Work through every gadget: the audio at a range of volumes, each seat's adjustment, massage and inflating side bolsters, keyless entry and start, the Comand screen and the sat nav. Ask whether the car has spent long periods standing.
Why it matters: Electrical faults are the more common problem on this generation, including failed amplifiers, inflating seat bolsters that stop working and keyless entry faults. A flat battery from standing can itself cause electrical problems, so a car kept on a trickle charger is a good sign.
Also in the full guide
- Dry carpets in the footwells
- The cold start, test drive and paperwork checks for the exact version you're viewing
The full guide to the W221 S-Class
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.