Merry Christmas all.

I have a MY93 jdm wrx wagon (td04) and overall it does run very well, when letting off of the throttle at boost the dump valve does its whoosh (newish bailey) and along side it at about the same time as the whoosh there is another sound, that i can only describe as a humming?vibrating type noise, not loud, about the same volume as the dump valve, it doesnt always do it, only really when warm and after letting off from high boost, the car has a oe airbox and filter, decat downpipe, straight thru decat exhaust, and thats it really. I havent tried taking the dv off yet but i might try that tomorrow, as i suppose it could be that? Any ideas on this one please??
thanks.

 

Have you checked all the associated hoses, at higher boost levels gases may be escaping from a damaged or loose hoses?

 

hi dan, the hoses are new samcos, all tight fitting, there is no flat spots or overboosting, misfires, or cutouts, and the noise only ever happens when letting off olongside dv, the car runs fine, which says to me its not the hoses.

 

Tis hard to say without hearing it myself... Faulty DV?

 

Correctamundo dan, put the oe recirc valve back on, which i planned to do anyway, and which will stay on now, and the noise has gone, sweet.