Hello!
I have a MTH 30-1607-1 Imperial Northern that plays the idle sounds along with the chuffs while the engine is moving. I run the engine conventionally so I dont know if there is a setting for that or not. None of my other MTH steamers do it so im guessing that there is either a setting for it or there is a problem with the sound file. I bought the engine a couple of months ago new in the box. Its done it since since new. Thanks.