simer4 wrote:What you are probably hearing is the air to air dual heat exchanger that is more evident in cab as it is part of the base cab stereo engine sound files.
Well, it's intermittent, just sometimes it's so loud I have to turn the volume down in a way that shouts "bug". But okay, I'll go fiddle with that, thanks. It might be something to do with running with/without alchemy on, I quite often forget to enable it.
There is one other issue, there's something dependent on RPM that's usually pretty high-pitched - possibly another fan - but as the engine goes to notch 1 or down to idle you can hear it reach the bottom of it's pitch modifier curve, and it sounds like you put your hand on a record turntable; perhaps add a volume modifier curve to fade it out at low RPM? I've had similar problems setting up turbocharger samples. Otherwise, this is a big step up on the involvement scale.