Hi guys,
Hope someone can help with this one because it`s really bugging me!MY93 WRX has been running super fine lately,until an annoying whistle has appeared on comedown. You can accelerate gently until the turbo spins up into affect(around 4000rpm)and then loose off (the throttle),and there is a distinctive flute type whistle.(between the drop from 4000rpm to 2000rpm).At first I thought maybe the dump valve was not shutting proper, but then surely this would affect performance? Not any slower,and still chucking 0.8bar according to gauge.If the car is drove hard, no noise is heard.Could something be on the way out? Please reply if you`ve any ideas.
Cheers Proby.