The timing chain of the longitudinal V6 diesel runs at the back of the engine, on the gearbox side, so replacing it means taking out the engine or the gearbox. That alone makes it expensive, but the mechanism is the point: the chains stretch and the hydraulic tensioners lose their pressure. The first and only early sign is a 2 to 3 second metallic rattle audible on a cold start. If that is ignored, the chain jumps or breaks, and the engine is badly damaged inside. The same chain kit also drives the oil pump: if that seizes, the engine is left without lubrication.

The four groups of parts in the air suspension (compressor, valve block, ride height sensors, air springs) work together, and any weak link causes a fault message, an uneven ride height or a car that settles. The characteristic symptom: the car sits down on one corner overnight, levels itself for minutes in the morning, and the compressor runs long and loud. According to the reports the compressor lasts 80,000 to 100,000 km; and a leaking air spring takes the compressor with it, because it keeps trying to make up the loss.