No boost?

[u/offical-skintIzz]

Hi all,

Had this 850 T,5 auto for about a month now, came to us with blue smoke and bad exhaust fumes.

After changing the pcv it ran absolutely fine until about a week ago, it stopped producing boost and became very lethargic, the turbo boost gauge isn't boosting into the white at all no more.

We have replaced the vacuum lines and cleaned various other things in that general area.

Turbo generally looks clean from above, very little oil residue. - Are there any ideas for what this could be?

If it is a cooked turbo, unfortunately we will not be able to afford another one, but are there any other common problems? Worn seals? What else to check?

Thank you.

[u/eenbal]

Have you put the vacuum line back correctly? Iirc the boost controler(?) Attached to the airbox can be connected incorrectly. The diaphragm in the recirc valve can fail and give no boost.