I've got a problem with my dump valve on my RS Turbo S2. At first the dump valve sounds perfect but then once the engine warms up no sound at all. All I hear is the light screamy noise of the actuator. I've got Forge 6-bolt twin-piston type dump valve.

I don't know what the problem could be. I checked the springs and they seem working fine. The dump valve opens and closes normally when I checked it. What I've installed recently and don't know but might affect it in someway is the stage 3 T3 turbo and a Blitz dual-solenoid boost controller. Anyone can help pls? Thanks