Engine misfiring and grinding sound!!

[SAT_GTI]

Hi guys can someone help me. Everytime i start the car there seems to a loud grinding sound for a few seconds and then disappears.. Also after a minute ir so the car misfires leaving a horrible sound like it struggles..

Now recently there has been white smoke coming outa the exhaust which has a weird burning smell..

Coil packs and spark plugs have been changed. Also pvc valve is new

[Paradox1]

Doesn't sound good at all.

Any codes?
do you know when the cam chain was last changed?
I wouldn't drive it, get it checked out asap

[pudding]

Grinding on startup and smoke that stinks - I'm thinking knackered turbo as worst case.  Hope it's not that tho.