Does this sound like N75 fault?

[its_neil]

My BAM S3 has not been behaving as I expect at WOT recently, there are times it feels underpowered (but smooth) when accelerating away but other times it almost decides that its an automatic 'kick down' and the power will surge back (i.e smooth, slow increase to 3500rpm then all of a sudden the turbo wakes up). I've owned turbocharged cars in the past and the symptoms point to a sticking wastegate or perhaps faulty boost management (hence N75) so do these symptoms match?

What is the part number for an 02 S3 BAM N75 valve?

 

[Westy]

Unplug the electric sensor on the N75 and go for a drive. This will make the car run on turbo actuator pressure which should only be 6psi but you should be able to tell if the turbo is still surging or doing anything strange.

I was experiencing over boost problems when my N75 broke. A new N75 is around £40 bur not sure of part number as I'm not at home at the moment.

 

[Y83OLK]

Mine did this yesterday, i put it down to the ESP cutting some power.

 

[S3 Nattie]

I put my original N75F valve and a green spring back in my DV back on yesterday which as far as I can remember my N75 was working fine before I removed. Im getting over/under boost problems, 19/4 psi according to my gauge and getting 2 fault codes so my J valve will be going back on.

 

[dplovin]

i got the same problem to...... ive done the n249 bypass and had the n75 unplugged for a while while doing the bypas, once finished plugged the n75 back and the car was running fine no hesitation at all, then 2 days later the faults appeared agiain damm, so westle unplug the n75 if the problems still there while driving i can count the n75 out ?

 

[S3 Nattie]

If the car doesnt change when you unplug the N75 then the N75 is faulty. As westle says you will be running a lot less boost with it unplugged and it will defiantly be a noticeable drop in performance if your N75 is working as it should. If there is no difference with it unplugged then your N75 needs changing.

 

[dplovin]

cheers mate i'll give it a go today