de pe net: I've not experienced this on the BMW, but have some experience with Turbo's in general from my Evo forum friends... I'd say it could be 1 of 3 things. The first is that you could have either a leak or blown off one of the intercooler hoses. These pipes take the forced air from the turbo and feed it through the intercooler (to cool it) and then into the intake. When this happens the air / fuel mixture becomes very erratic and usually a very rich fuel mixture is used hence the excessive use of diesel. The erratic fuelling will cause the stuttering issue. This is probably the cheapest issue to resolve, however, if it only happens at low rpm (ie when using the smaller turbo and not the larger turbo) then I'd say this is unlikely to be the cause unless the hose problem is where it is connected to the smaller turbo. Any further along the airflow and the problem would be more consistent across the rev range. Second is a faulty actuator / blow off valve. The actuator controls the boost level in the turbo and the blow off value vents excess pressure past the turbo as part of the boost control. If the actuator has become stuck it could be that the turbo is not being allowed to generate boost properly. You mention a wooshing sound when you come off the throttle, this is the blow off valve opening to release the turbo pressure to prevent turbo stall which is normal, although I've never been able to "hear" it in my BMW whereas the Evo blow off valve sounds like an air tank releasing pressure every time I change gear! The BMW uses a closed ventilation system I believe, so when the blow off valve opens to release the pressure in the turbo housing it is vented into the cars exhaust rather than to open air. I don't know if actuator problems are common on BMW turbos but I think that this would where I place my bet at this point. Thirdly is a blown turbo. However, I would suggest that this would be significantly noticable in driving. There would be a big difference in low rpm power, followed by a big kick in the back when the larger turbo comes on. Im not too sure if this is likely to be the case, your post mentions hesitation but then also mentions no power at low rpms so difficult to know exactly how the car is driving. In any case, I would say the problem lies with the turbo setup somewhere and you need to get it looked at before you go on a long journey. Hopefully it's not the turbo, especially as your car isn't that old. How many miles have you covered? Let us know how you get on. sau http://www.bmwland.co.uk/forums/viewtopic.php?f=5&t=127579 si asta cred ca e ceea ce ai tu http://www.bimmerforums.co.uk/forum/f15/2005-e61-535d-loss-low-down-power-t83303/ din simptome seamana.