Is this the one that goes into the Rocker Cover ? The little breather looking device with a tube that runs down to the intake manifold ? Pete -------------------------------------------------------------------------------------------------------- Pete, I believe that that's an oil breather, similar to ones in Hondas. Im thinking it the one you can see as soon as you open the engine bay? AJJ, I talked to another mate, and I may be something to do with your waste-gate. Also, if you've just gotten a new Air box panel filter, it may just be letting in more air as its clean, thus the waste-gate won't release quickly enough, thus you get the 'tututu'. By the way, if the sound is a 'chuuuu' that's not your waste-gate. When you open the engine bay, and you cant actually see any hoses loose, just listen for a small vacuum sound. If you can hear it, well obviously a hose it loose :D In the end, it shouldn't do any real damage, so ive been told by a mate of mine who used to work on BA's and BF's. Ive attached a picture with what I think Pete is talking about, and where the vacuum hose is that I mentioned in my first post. Its tucked right in behind the intake, and its quite hard to get to. Gypo.