Models · Mercedes-Benz
Mercedes-Benz Viano W639 buying guide
The Viano, the people carrier version of the W639 Vito van, sold from 2004 to 2014 in three body lengths with rear-wheel drive. It shares the van's reputation for mechanical strength, and most are CDI diesels.
The versions
- CDI diesels: 109bhp and 150bhp four-cylinders at launch, later a 3.0 V6 diesel
- 3.2 V6 petrol (218bhp) at launch, replaced by a 3.5 V6 (231bhp) from October 2004
- Six-speed manual or five-speed automatic, driving the rear wheels
- Three body lengths on two wheelbases: standard, long and extra long
What to check on a W639 Viano
3 model-specific things to look at when you view one. They're a starting point, not the full inspection.
Diesel injector seals and glow plugs
What to look for: With the bonnet up, look at the tops of the injectors on the engine for black, hard, tar-like deposits around their bases. Start the engine from cold and check the glow plug warning light goes out and stays out.
Why it matters: The Viano shares its CDI diesels with the Vito van, where loose or badly sealed injectors are a known fault: a carbon build-up like hard tar forms around them and saps power. A glow plug light that comes on and stays on means a new set of plugs is due.
Turbo boost and limp mode
What to look for: On the drive, accelerate firmly through the gears and feel for strong, steady pulling once the turbo comes in. Note any flat, gutless spells or the engine dropping into a reduced-power mode, and check the brake lights work.
Why it matters: On the Vito, which shares the Viano's diesel engines, the boost control valve is a common fault that leads to low or no turbo pressure. Intermittent switching into limp-home mode and faulty brake light switches have also been reported. Both are known and fixable.
Rust on earlier vehicles
What to look for: Look along the sills, the bottoms of the doors including the sliding doors, the wheel arches and the tailgate for bubbling paint or rust, and under the car with a torch.
Why it matters: The Viano shares its body with the Vito van, and earlier Vitos suffered from rust, with build quality improving greatly later on. A later vehicle, or an earlier one with clean or treated metal, is the better bet.
Also in the full guide
- Rear seats and floor mountings
- The cold start, test drive and paperwork checks for the exact version you're viewing
The full guide to the W639 Viano
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.