1.4 TDI CUS/CUSA engine failure

[Neal F]

Hello, Just wondering whether anyone can shed some light on this problem. Have a Polo 1.4 TDI engine code CUS that came to me with a pretty loud banging noise when running near the gearbox. Suspected the DMF, removed starter motor and the flywheel was very loose and noisy. Have fitted a new VW solid flywheel kit, re-started engine (just to briefly try as it was booked in to VW for re-programming due to solid flywheel kit) and the flywheel was quiet but there is a heavy noise from the bottom end of the motor. Stripped the sump off, and number 3 big end has a lot of play in it, so it must have been starved of oil. Plugged in diagnostic scanner, and there is one fault code only relating to an incidence of low oil pressure (historic, not current). I suspect the owner has been driving around for some time with a worn DMF, is there a chance that the vibration may have caused partial failure of the oil pump, or affected number 3 big end somehow? It was full of oil, has a fsh (last done 3 months ago) and has only done 40k, 2015 car. If anyone has some ideas or suggestions that would be appreciated. Thanks.