My Fabby TDI has been checked out by IML at Plympton and they tell me the 'BOOST PRESSURE REGULATOR' valve is faulty. They are going to replace it to see if this cures the problem.

Apparently if this valve allows the boost pressure to get too strong a safety device cuts in to stop it - they say this accounts for the sudden loss of turbo boost - DOES THIS MAKE SENSE CHAPS? :confused:

Sounds exactly like the TDi version of a dump valve, so eminently believable, yes. How much will it cost?

Definitely believable - one thing good about VAG engines is they will kill the engine when something goes wrong which a) prevents further damage being done and gives a good clue to the driver something's wrong! "Why's the f***ing thing going so SLOW??!!!"

Sounds like what would happen if the boost pressure solenoid was faulty and the wastegate failed to open (although I dunno if any of this applies to the turbos fitted to diesels).

On my scooby if either of these failed the boost would continue to rise until the ECU caught it and cut the power due to a built in safety cut, but on high spec cars nothing stops this happening too late as a momentary over boost is enough to wreck an engine!

Sounds feasable to me.

The regulator opens the acutator that controls the vanes in the turbo. The PD turbo doesnt have a wastegate to control boost, they just alter the geometry of the vanes to regulate boost. Sometimes the solenoid (or regulator valve) sticks and boost is lost.

Sounds feasable to me.

The regulator opens the acutator that controls the vanes in the turbo. The PD turbo doesnt have a wastegate to control boost' date=' they just alter the geometry of the vanes to regulate boost. Sometimes the solenoid (or regulator valve) sticks and boost is lost.[/quote'] Quick question, if this solenoid sticks, can it make the engine sound like it has a dump valve, because mine has this problem and the dealer hasn't cracked the problem yet :(.

So far the dealer has had the car for 1 day, then 3 days, then 4 weeks and 1 day, and it goes back in about a weeks time, they say the've changed virtually everything related to the turbo (including the turbo), last change was a complete set of vacuum pipes (breather system), as some of them were blocked - this made a difference but it still ain't fixed :thumbdwn:

Vince

Oh yeah, mines usually a Superb TDI PD 130 - but now often a Superb SDi.