So my 330d has developed an issue and I'm at a loss as to what to try next.
Basically, it accelerates fine up through the revs/gears (if a little sluggish than it used to be)
But if you are in any gear and rev it up to 3000 odd and then let it drop down to about 2400 without changing gear there is no acceleration (i.e. turbo doesn't engage) and it stutters along until the revs slowly build back up. (Quite smokey)
If you shift up a gear when it is struggling, the revs drop as expected and then turbo kicks in fine etc.
So it only really happens if you are hammering it hard and then let the revs drop without changing down. Or if you drop down when the revs will by high in the lower gear.
Took it to my indy to read the codes, had one MAF fault, cleared it, cleaned the MAF - No difference.
Disconnected the MAF completely and gave it a good run - No difference
Cleaned EGR to rule that out - No difference.
I don't think it is the turbo as its still going fine up through the gears or if you floor it from low rev's.
No obvious leaks from the turbo pipes/intercooler (had a split pipe before which exhibited very different behaviour)
My only guesses at this point is a possible blocked cat or sticky injectors?
Can anyone advise how to test this or if they found another way to solve this issue?