ok so i have a weird problem so i bought a 97 audi a4 from a friend for cheap because the wastegate was broke and he put a 10pnd spring on it witch works great boost to 10 pnds no over boosting, anyways it has an intake adapter on it with a cone filter, and i started to notice an annoying WOOT! noise right around 5in vac, and it appears to be coming from turbo side so i thought maybe a loose intake so i checked everything and its all tight no leaks from what i could see and i did a boost leak test to see if there was any leaks and not a 1, so if anyone has any ideas on why my car makes a loud WOOOOT! noise at 5in vac please let me know.

car specs
97 a4
awd
5 speed
turbo
113k miles