Other Fuel System Pump problems of the 2015 Volkswagen Golf

Rust on fuel filter housing discovered during 60k mile fuel filter change of 2015 Golf tdi (see photo). Told this can lead to potential major damage to high pressure fuel pump if particles come off. Only use high-quality diesel so not sure how this happened.

At less than 20,000 miles the glow plug light started coming on while driving at highway speeds and then the vehicle loses power, dropping down to about 30mph. Shutting engine off corrects but will reoccur next time vehicle is started after being parked for the day. Then the check engine light and service now lights also come on. Took to vw dealer, after 4 hours told it was a fuel problem with metal in the fuel. A sample must be sent to vws lab and it will take weeks for an answer. They are presumptively blaming bad fuel and will not cover under warranty. I believe the fuel pump is the source of the metal in the fuel as there has been a bearing squeal noise for about 2 weeks before this happened. I don't have any documents to attach as they still have the vehicle at the dealership.