Since about a week ago, I have noticed a strange chirping/metal grinding sound coming from the turbo side of the engine bay whenever I reach about 3500RPM or just by quickly pressing the throttle, no matter what gear I'm in.
The car is a 1995 jdm wrx, 84000km and the only mods are catback exhaust and hks air intake. All the brakes, transmission, clutch, drivetrain are stock.
Popped the hood and got a few people to listen to it but hard to diagnose where exactly the noise is coming from. My dad suggested possibly the turbo wastegate, but I don't think this is the issue as it sounds more like a metal screeching too me than an air leak. Could this be something inside the turbo?
Thanks for your suggestions