Hi all i'm after a bit of advice there seems to be some pretty clued up BMW guys on here.i've coppied this from my newbie post.
I've been running my touring for about a year now and i've had one or two niggling issues with it. The main one is a lack of power, when cold and in the early stages of warm up, this comes with what i can only describe as a slow speed rotating catching noise, i first thought turbo but it aint rotating fast enough and as the revs increase the noise slows down. afeter a short time i can feel a slight 'bump' as if somethings activates or closes then away it pulls, with the issue not to return again till another day. It was very bad when i bought the car, it only became apparent on the drive home after handing over my hard earned, on a slight incline on the M1 the power just fell away and it struggled to keep anywhere near 60/70. however over time it seems to have got loads better. Swirl flaps done, fully serviced with quality oil and parts including breather. No fault codes stored so i'm a little in the cold whats the problem.
Gotta say though when its warm it pulls fantasticly with very little noticeable smoke. This was untill today the rotating noise has been coming on intermittently today then after about an dhours driving the power just fell away, litterally no Turbo action at all 15 minutes later all back and running fine. No Mil lights or other warnings the last time i had it checked at garage there had been no stored fualt codes.
I'm pretty handy with the spanners, just a bit green with the bMW problems.
I need some help, i've threatened him with the Autotrader/Ebay.