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Discussion Starter · #1 ·
Here we go. !997 2.5Tdi ACV. There's something behind the expansion bottle that has a load of vac pipes and a few multi connectors going into it. Can't read the part number. It's black plastic with a metal dome on top , about the size of a *** packet.
Can someone tell me what it is and why it now buzzes for about 5 seconds when I knock the engine off.
Please tell me good news !
 

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Lets have a picture, its either the EGR control solenoid also called the N18 valve (which you can unplug with absolutely no detromental effects) or the boost control solenoid also called the N75 valve (controlled by the ECU, and vents boost pressure when it reaches its maximum level).
 

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Discussion Starter · #5 ·

Can't upload the photo I took. Found this piccie.( Have tried to put a link to it). So I assume it's my N75.
Why would it be buzzing/ vibrating when turning the engine off? The wife reckons it sounds like groaning pipes in the house.
 

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Discussion Starter · #7 ·
anyone? Mine is a bit different from the one pictured. It has a pipe coming off it with what looks like a small paper filter. Looks a bit like an old style fuel filter.
 

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Discussion Starter · #9 ·
most of the part number has rubbed off. Does anyone have it.
Have just been doing some reading. There are a few threads on the T5 forum describing my symptoms . all of which point to the n75. Any other noisy t4 n75's?
 
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