B-Classbuyer's guide

The W246 B-Class sells itself as practical, efficient family transport — and the best examples are exactly that. The problem is that a neglected timing chain, a gearbox with unchecked fluid, or a diesel that has spent its life on short runs can erase that appeal fast. Early cars in particular need the most thorough checks, but no W246 should be bought without a cold-start, a proper road test, and a diagnostic scan across all modules.

This guide covers ten documented issues: timing chain or oil-service risk, automatic/DSG/ZF gearbox harsh shift, coolant leak or water pump fault, diesel DPF/EGR/AdBlue fault where fitted, infotainment/software electrical faults, suspension arms, bushes and tyre wear, brake corrosion or EPB fault, panoramic roof or boot water leak, ADAS/radar calibration fault, and recall/campaign status. Each fault has a field check and a real repair-cost range.

A well-kept W246 with a full history and a clean scan is a sensible used buy at any point in the range. A car with gaps in the service record and a seller who won't let you scan it is a different proposition entirely — walk away or price the risk in.