I have a Lehigh Valley Hudson, one of the first P3 steamers out, and it does exactly what KBTT describes. I mentioned this in an earlier thread, but thought it might be just lucky me. I guess not. When this problem is figured out, you'll be getting my engine to fix Ralph. I put it on the shelf for now as it is a pain when powering up the layout. Let me know when you know please.
George