I have had my car from new. Far from faultless, the Turbo blew at 46K (and BMW didn't want to know) but it now has 60K on the clock.

For the last 20K it has felt flat below 2,000 RPM and treated the following car to a cloud of brown/black smoke under hard acceleration, especially in kick-down.

After some web research I self-diagnosed a clogged or faulty EGR (Exhaust Gas Recirculation) valve and had the EGR replaced during a service today.

My word it is like a new car!

Instant pick-up, urgent at any revs, no smoke and on a mixed road 70 mile round trip this PM it returned 58.3 MPG. I haven't seen 50+ MPG for 3 years, rarely much over 40 MPG and down to even sub-30 locally..

If you have a disel displaying anmy of the above symptoms, get a new EGR (£120). It is a revalation.

Edited by Woody37 on 19/04/2013 at 23:14