if the starter engages and turns over the engine, i wouldnt worry about the Duel Mass Flywheel.
Its only when it spins but doesnt turn the engin ove the DMF is starting to break up and put crap in to the starter, if the DMF IS breaking up you will see iron filings in the starter.

Have you any fault codes if so get then read, its the quickest way sometimes, if you dont have fault codes then check for a leaks or somewhere where there may be a pressure drop in the fuel system.