[Gt5500]

Been having issues with my 2006 330d with lack of power, I did have dpf problems but thats all clear now and in gt1 dis the back pressure is minimal.
I was convinced it was boost related but dis shows the boost as within spec compared to the expected. I checked that the vnt actuator moves on startup which proves that the actuator can move and the arm is not seized, however I have now discovered that when the engine is revved the vnt actuator never moves even if the pedal is floored quickly it never moves .
This sort of points to the map sensor as being the problem but it's odd that the boost pressure level is showing as close to expected in diagnostics. Can the vnt actuator fail in a manner where it moves from open to closed at startup but does not respond to requests during running? Seems unlikely, I'm thinking it's more likely the map sensor is not reporting correctly so the ecu never tells the actuator to open either that or I could have a boost leak somewhere.
Thanks in advance.

[Yozh]

Your VNT actuator will not necessarily move when you rev the engine in a stationary state, there is not boost request at that point most likely. I would suggest you pull the codes. If it is the VNT actuator, as it is electronically controlled, you should be able to see it in diagnosis. Other things besides the map sensor to check is the MAF and the IAT sensor.

[Gt5500]

Originally Posted by Yozh

Your VNT actuator will not necessarily move when you rev the engine in a stationary state, there is not boost request at that point most likely. I would suggest you pull the codes. If it is the VNT actuator, as it is electronically controlled, you should be able to see it in diagnosis. Other things besides the map sensor to check is the MAF and the IAT sensor.

Really? I have seen a video on YouTube of a 330d with electronic actuator and it can clearly be seen to move when the engine is revved even lightly, many other posts on various forums talk of it moving too. Mine did not move once even if the pedal was slammed to the floor.
I should have mentioned that I have used dis gt1 and inpa and none show any faults, and as mentioned the charge pressure level matches the expected level in dis at various throttle positions.
The MAF was changed recently as preventative maintenance and the IAT seems to report the correct temp (it was reading about 30 deg. C with ambient about 7deg.c which I would guess is about right as the air is compressed and run through a hot turbo.
I think there may be a slight boost leak where the intercooler pipe connects to the turbo as there is a bit of oil mist around the flange, but it is minimal could that be the problem?

[Yozh]

In US/CA we have 335d with a bi-turbo set-up that is vacuum actuator controlled. Your best bet is to check on the Euro side of the forum where there is more experience with your specific set-up. Is there a way to diagnose VNT controller easily?

[Gt5500]

Originally Posted by Yozh

In US/CA we have 335d with a bi-turbo set-up that is vacuum actuator controlled. Your best bet is to check on the Euro side of the forum where there is more experience with your specific set-up. Is there a way to diagnose VNT controller easily?

Ok thanks, can a mod move this to the euro side then so I get more response. Cheers.

To answer your question I believe there is a test that moves the actuator in dis, I haven't found it yet but I'll have a look.