[Alex320]

I had the turbo replaced on my 06 320d auto about 2k miles ago (last one failed) it was running sweet for the first 600-700miles, the all of a sudden I was getting the odd lurching/surging feeling, it has gotten progressively worse (but has peaked now) it feels like the car is mini shifting gears, boost comes sort of delayed and I'm getting a grumbling sound on down revs when I let off throttle, above 2k revs everything seems to run normal. I'm at my wits end with it. So far I've..... Changed air filter, cleaned maf, changed maf, cleaned egr valve, changed egr valve, smoke tested and found no obvious boost leaks, serviced gearbox (thought it was the auto box at first but now pretty confident it isn't) put new intercooler on as it was a bit oily from the previous turbo failure, tested battery and it is reading correct voltage running and not running, car is giving no fault codes or eml. The other strange thing is it doesn't seem to run any worse if I unplug the maf, or the egr vac line (although this does trigger codes on my reader. Any help would be appreciated, I think I'm going to try the turbo boost pressure solenoid next.