Having given my local Skoda garage £370 to flush contaminated diesel from my Superb estate, a serious cold-start knocking issue persists as bad as ever, disappearing once the engine is just a little warm. A phone call to a local independent VAG-Skoda specialist this morning has thrown up another option, where the mechanic immediately suggested that the issue was with a failing Dual-Mass Flywheel. Upon mentioning this idea to Skoda, they insisted that fuel contamination was the issue, and that I should run the car for at least another 400 miles "to fully flush the system", before I think about further investigations.

I would have thought that if fuel contamination was the cause, flushing/cleaning the system would be an immediate fix, and would not require several hundred miles to complete. As I'm working in Ireland for a few days next week, I will have an opportunity to leave the car at the specialist and get all the DMF work done before I return, as Skoda will not be able to undertake further investigations until much later next week. Whilst all the fuel contamination work was explicitly excluded from any warranty claim, I am assured that failure of the DMFW will be covered. I would appreciate your guidance.