Any PS1 steam smoke unit that is the same size should work. Just transfer the little brass funnel cup to the new one and you should be in business. What's wrong with the current smoke unit? The resistors, wick, and motor are available from MTH.
Sometimes the front truck , sometimes the drivers, and sometimes the rear truck. I first noticed one rubber tire coming loose so I replaced it but that didn't help. Then I thought it might be the wire being twisted that plugs in the back of the engine but that didn't help. Did I disturb something by removing and installing the shell numerous times?
Thank you. Of course the whistle blows at the same spots which is under a tunnel or an almost unreachable part of the layout. It seems when the whistle blows if I increase the voltage it stops. I tried cleaning the track with my Lionel 3927 Track Cleaner. I will see if I can find a way to clean it better. Thanks again.