replacing tender whistle

I have an old 2025 and 2466wx tender. The whistle on the tender is two tone and is generated by a small impellor that forces air out of two ports. Air comes out of both ports, but only one actually makes a whistleing sound.

I suspect their is a leak somewhere so I was going to try and seal the outside with some caulking. Does anyone know of another reason I’ve lost half the whistle?

My second question is, would anyone have a recomendation for replacing the whistle with some upgraded sound options?

As always, thanks for the advice.

I had a similar problem with a Lionel 2671w. I had a peice if fuzz stuck in one side. Try vacuming it. Its worth a shot. If you give up on it; sometimes they sell the whistle unit on ebay for around 20 bucks.
Good Luck