oops, looks like I got a reply while I was typing my last question.  I like the idea of a transition car.  thanks. 

thanks, but I've already set up some Bachmann track that I purchased the other day.  The idea was just to provide a train for under the Chrismas tree.  (The TYCO track was nailed to a piece of plywood years ago and I have no idea where that is)  I've spent hours cleaning the motor (plastic safe contact cleaner), but it still runs slow and you have to gently push it to get it rolling. (It actually sounds like a bunch of rocks rolling around in there) You are correct about the TYCO couplers, they look like can openers.  Maybe I'll work on the TYCO engine some more.  Is there a jury-rigged way to make the Bachmann engine work with the TYCO cars?  

I pulled out an old (35 years?) Tyco HO train set to put under the Chrismast tree.  The engine has seen better days and is very noisy and very slow.  (I spent several hours cleaning everything to no avail)  I noticed the local Hobby Shop carries Bachmann engines so I was going to purchase a new one.  My question is, will the coupler on the new engine match up with the TYCO cars?  There is nothing wrong with the cars.  Thanks.