Check the motor brushes?
I agree that motor overheating is the culprit. The first thing I would check is between the segments of the commutator. These get plugged up with carbon from the brushes and over oiling adds to the gunk build up.
This gunk is conductive and creates a pathway for electricity between the segments. Cleaning it out is easy; just take care not to hit the windings.
If this is a can type motor you will have to disassemble it.
I have a Life-Like Geep that had a similar problem. A small drop of oil on each motor bearing brought it back to life, so to speak.
Simon
Welcome to the forums.
As Mike says, look it over. My thought is that the motor is getting hot. A drop of oil in the right place may work wonders.
Fellow I know had one, ran OK, oiled it, ran a whole lot better.
Good luck,
Richard
Welcome.
How do your other locos run? Do they stop around the same place?
You did not give us much information. DC or DCC?
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
The first thing I usually do in diagnosing a locomotive issue, is run it with the shell off, watch, listen, and feel for anything getting hot, or warmer than it should.
I assume this is DC ?
Mike.
My You Tube
I have a LifeLike Proto 2000 E8 I bought on Ebay that starts off just great but as it continues to run for several minutes it gets slower ... and slower ... until it finally comes to a stop. I've looked for an answer all over the internet but only find folks with issues of cracked axle gears, dirty track, dirty wheels, dead frogs, etc. The problem is none of those. Anybody have any ideas?