I recently purchased a 2004 535D model from the UK and had it remapped in order to up its torque and bhp, really good fun however just yesterday it looks like the large turbo is not kicking in after the smaller one. A few weeks ago i had the same problem with the smaller one but after having a look below the engine cover i noticed a vacuum pipe that came off, i put it in place again and all is well now.

Could the problem i have with the large turbo be similar to what i had? a little guidance would be appreciated because i want full power back :-)

d.

 

Just found your thread.. I just have a problem with the small turbo. Are you saying the vacuum pipe came off and when you reconnected it all was well? Sounds like an easy fix, any chance you are alive on this forum and have a pic from underneath?