My question is, is the wastegate on the K04 vacuum controlled or pressure controlled.

My issue, couple of days ago I took out my N75 valve because I was having some issues and I notticed one of the vacuum lines was pinched. When I put the N75 back in and drove the car, I could not boost past 4psi. I left it for a day like that because I didnt mind that much plus saved some gas. Today I was running some tests to see what the problem was. I hooked up the compressor line straight to the waste gate to see if I would get max boost, but it still would not go past 4psi. So then I had an idea and I connected the waste gate vacuum line to the intake/charge pipe and I plugged the compressor line. I tried that out and that got me to 20 psi which was what it was at before so I was happy. Next thing im going to do is order a mbc, and see if that helps.

Any one have any ideas or thoughts, I would appreciate the help.

 

It's pressure based. It receives a vac line from the charge pipping. There is a 4-5psi spring inside and when the pressure gets near that amount it cracks open and stays open to maintain that pressure.

 

So why wont it go past 4 psi when i connect the waste gate directly to the compressor housing?

 

Because there is no boost control. The only thing regulating psi is the waste gate and that's set to 4psi.

 

Ok so youre basically saying when I get the mbc my problem would be fixed?

 

Mbc or n75 between boost reference and wastegate

 

Ok thank you sir! I ordered my MBC so ill update on status once it comes in.

 

Just put in the MBC today, works like a charm. So happy to have my boost back!