This is a weird one guys and girls so I was just wondering please has anyone else had this. Ok we all know it's cold at the moment, but when I finish work around 8/9pm and the temp has dropped more, as I pull away up the road, as the revs go up, I get what I can only describe as a howling noise like an owl, howling as the revs go up, after a few minutes as the car warms up the sound goes and not to be heard again once the cars warm. Turbo has been refurbished from Liam D and has done a max 12,000 miles, I can only think there is a boost leak somewhere. Would like some opinions please guys if anyone or knows anyone who's experienced this. Thankyou Pat