My 2013 VW Polo GTI went into limp mode recently so I nursed it to the nearest service station. The call out mechanic managed to diagnose an issue with the supercharger clutch. He advised that the supercharger is a sealed unit and that the fault related more to a manufacture fault rather than a running fault. Once towed to the local VW service centre they have stated it is the water pump that needs replacing and there is an interface between this and the supercharger clutch (hence the initial diagnostics). We have applied for the VW Good Will application, but have a feeling they will wriggle as much as possible. Would we have a case to claim against the water pump, or is this normal maintenance for the car?
If it is the water pump as the VW people have diagnosed then I doubt you would have any claim. Water pumps do wear out like any mechanical component, and yours is six years old.