I think something is wrong with my Factory boost solenoid circuit...

I took the WRX for a drive today, When i stopped at idle.. I could hear a weird constant "ticking" noise.. It's not the injectors.. That's a diffrent ticking noise. It's coming from the boost solenoid... I unpluged it (cable, not the vac lines) and the ticking stopped. You could also touch it and feel it vibrate. (It was quite hot to!)

When i unpluged it there was no change to the car at idle.. It still idled ok.

I presume it's being turned on and off in quick succession... Is it swiched through a relay? Or is the ECU turning in on and off directly? It's never done this before. I don't think it should be doing it eigher..

Any help would be great.

Thanks,

Tim.