FuriousFocus

Hi all, I have a 2006 focus 2.0 TDCI (136) and recently it's started to have some weird turbo problems.

It started by feeling sluggish and not boosting as it used to at low revs. Now it's started doing this thing where whenever I put my foot down and go above 2500-3000rpm the turbo boosts up to about 75% and then completely dies. It feels like a valve opens and lets all the pressure go but the engine carries on revving. I can tell it's the turbo as I have a pressure gauge and it reflects what I have just explained.

I was initially worried that it was my turbo gone but then the other day I was sat in traffic and I guess it got hot and this fixed the problem! But now it has come back again. So I'm guessing it's something electrical or maybe a malfunctioning/sticky valve?

I've checked for leaks in all the turbo and intercooler pipes but I can find anything. When boosting you can hear a whistling noise though (although it has always made this). I've also got the EGR valve blanked, but it has been for a year so don't think this is causing the problem.

Any help anyone has would really be appreciated!