I have a Lionel 6-85367 Railsounds diner. When I create a lash-up and activate the ( any command engine) whistle or horn, their is a clunk sound from the dining car. I have played around with volume settings, but the clunk just gets quieter along with the dialog.
Any ideas would be useful, and appreciated. It happens with Lionel, Atlas and 3rd rail with TMCC.