Part identification

[skwerl]

Hi. can someone ID a part for me please.

Small grey, plastic gizmo with an electrical connector and 3 small bore (around 1/8" maybe) vacuum hoses. The smallest hose is about 2" long and connects to the inlet Y-pipe on the right side, just before it meets the throttle body.

Thanks

[jpflip]

This is the valve that control the waste gate and it is sometimes called the N75. The parts catalog call it the cycle valve and the part# is 996 605 155 00

Edited December 6, 2020 by jpflip

[skwerl]

Great. Thank you

[Silver_TT]

For my own understanding I wanted to clarify, you are talking about the waste gate on the turbo itself, correct?  Basically a diverter valve to vent exhaust gases to control the speed of the turbine (and thus prevent over-boost).   Is "N75" also a Porsche term or is that a general term?  The reason I ask is because this is a common issue on some Audi engines and I has always assumed the "N75" term was Audi-specific.

[jpflip]

 If you follow the vacuum line from the cycle valve (N75)#44 you will see it split in two #38 (near the top of the oil tank), and goes to the waste gate on both side.  I cannot answer your question about the term N75 because the first time I've learn of the existence of this term was on the TT forum....I used it after 😉 No experience with Audi.... One day a guy came to my place with overboost problem and I immediately went to this cycle valve and found it disconnected from the intake...

[Silver_TT]

Ya that makes sense, thank you for the information.  I believe "N75" is a VW/Audi specific-term (anyone feel free to correct me if I'm wrong), although who knows Porsche is under that umbrella now too.... but the principle is the exact same as far as the way it works on both cars so if it's not officially called N75 for Porsche you certainly could call it that anyway because it's the same thing.  I was just curious, thank you.

 

And, yes, you are very wise.... if I ever get any boost faults that N75 will be the first place I start. 

 

Much of my TT experience/knowledge has translated well to the Audi TFSI, which I didn't initially expect.  I would definitely never compare the 2.0T to the Mezger, don't get me wrong, but it's amazing to me how much technology is shared between these cars.  I guess that's a hat tip to the Mezger, which is 12 years older, but can still run with cars 10-15 years newer engine technology-wise.  That's pretty incredible from a technology perspective; it's an incredible engine.

[jpflip]

When the technology is good and proven why not reuse it! Indeed this engine is a technological beauty ... My only concern is the cold start growling ..... But we should start a new thread for this one or continue and old one from 2008!!! 😉

[Silver_TT]

🙂  thank you again for the information!