Cold starting rough

[purpledansa]

Hi
My mark 6 sounds very rough and takes 3 or 4 attempts to start when cold. Drives and sounds ok once started. After only a short drive and standing for an hour or so will start again fine.
There was also an engine whistle for a couple of days at higher revs, that has now stopped.
Mechanic is guessing at a flywheel problem and wants to replace flywheel, clutch and starter (the clutch seems fine to me), and also suggesting a turbo problem for the whistle.
Any other suggestions?
Many thanks.