Trucks had a problem for 5 years now of white smoke on start up and idleing rough until it warms up also cuts out when flooring it with the chip turned up so I just installed new injectors 2 years ago thinking it would fix it but didn't. Now with that out of the way last night I was getting off the highway and when I let off it started knocking but kinda went away after u get up to 55 but then starts knocking bad at idle and then I noticed it was rolling a grayish white smoke bad. Sounds like injector knock to me but u can hear it really loud out of the exhaust and when I shut it of I could hear a grinding noise from the turbo until it stoped spinning. But I can spin the wheel freely and has no shaft play and won't make the knock anymore that it's cold but still runs rough and smokes like crazy any help would be appreciated