I just purchased my first MKIV. The car is a 94 6 spd with 28k original miles. No mods, still in sequential. The car is immaculate. Everything seems great except for a noise that I hear at heavy throttle through boost. It's not the "death whine." As the R's accelerate through 4000rpm I get that bit of hesitation which I've read is normal, but I hear this very high pitch sputtering or squealing noise. Sound like a super high pitch whistling but sputters. It almost sounds like air is being bled off. Once the large turbo kicks in, it goes away. I've searched on this, but it's too wide of a topic to narrow down. Can anyone please let me know if I should be concerned (which I am) and what I should look for as far as any leaks or anything goes. After this, I'm thinking my first purchase should be a boost guage. Thank you!