Hi everyone,

About 2 weeks ago my car suddenly decided not to provide turbo boost once it had been driven for about 20-25 minutes. At 3,500RPM, the supercharger disengages and the turbo doesn't cut in. This results is a sudden, noticeable reduction in acceleration and the boost gauge on the dash drops from full boost to about 25%. When cold, it works just fine.

I took it to my mechanic and he ran the codes and it identified an N249 diverter failure, which he replaced with a new part. He said it was a newer revision of the part too. However, the problem still remains, although once in the last 3 days, it failed to have supercharger boost as well.

The fault can be reproduced each and every time and the turbo doesn't return until the car has cooled down.

Interestingly, when it works as normal the car seems to accelerate a bit harder than before maybe as a result of the updated/improved N249.

It's booked in for next week to have another look but I was just wondering if anyone else has experienced similar issues and how easy were they to resolve.