I have this really annoying chirp when accelerating but most noticeably, intermittently at idle. While at idle, it starts when the fan starts, but then fades out even while the fan is still going. I replaced the fan, but it's still making the noise. On closer inspection it seems to be coming from the motor side, almost like the intake before the manifold. Could this be reverberating up from the Turbo? Does the Turbo kick on with the fan at idle?