Originally Posted by MisterSkiMask
‘While they were in there’ they found that the turbo was ‘coked up’ soot had accumulated on the exhaust side of the turbo and was almost to the point of interfering with the turbo’s operation, it had to be rebuilt.
For the 335d I would definitely remove the tune or dial it to its lowest setting before any long road trips. It is important for these modern diesels to get up to temperature and work a little as designed to keep soot from accumulating. I would also dial it down for mountain driving where the engine will be under constant load and have the opportunity to work a little as it was designed to without having excess fuel put into the system.
MSM, thank you for relaying your experience - this should be a cautionary tale for all of us. Did the truck have a DEF system? I'm wondering if the action of the DEF in our cars would tend to diminish the sooting you described in the turbo.