Im new here, so forgive me if this has came up recently.
Ive got a 2006 120d M sport edition, owned it for about 5 months. The turbo was making a really bad whining noise, so we bought a reconditioned turbo and a mechanic friend fitted it for me.
When the recon turbo was first fitted the car would idle fine but the accelerator wouldn't work, this problem is now solved but there is a sucking / blowback noise once the accelerator is let off.
Just wondered if any of you have come across this before and know what it may be? It's not showing any fault codes and there's no obvious problem that he can think of.
Thanks in advance guys.