Bachmann GP30 w/DCC. Peridically pauses, take right back off.

[buzzard975]

I have the Nickel Plate Road GP30 DCC loco.  Got it recently and until a couple days ago only had about 30 minutes of run time.  The day before yesterday I decided I would let it run for a while to break it in.  I set it about half throttle and ran it for 3.5 hours straight.  It was very uneventful and I could already hear a reduction in engine noise.  The next night I figured I'd do it again.  But this time, after about 1.5 hours it came to a very brief stop, then took off again.  Then a few minutes later, it did the exact same thing.  Then again.  The stops are VERY brief.  As soon as it stops it starts again.  I put a lighted car on the track to see if the voltage was dropping.  Well the next time the loco stopped, the light did not even flicker.  The next thing I did was run my FT-A at the same time.   I did that for about 10 minutes but the GP30 never paused again.  I think I will try that again tonight.  My track is very clean (just cleaned it), and the pauses don't always happen in the same place.  Very strange.  It does seem like it has to run a while before it starts pausing.  Is there any sort of protection built into the decoder to shut down when too hot?  Even that doesn't make much sense because it can pause once, then not pause again for another 5 minutes. 
Guessing I might have to send it to Bachmann.  This would be 2 out of 3 locos I've had issued with.  The last one just flat-out died after about 3 hours of runtime (not even continuous).   Starting to think the Bachmanns are junk?

[Jim Banner]

Could be an overheating decoder shutting down momentarily to protect itself.  This can indicate a binding or a lack of lubrication.  Not shutting down when running a second locomotive tends to confirm this diagnosis as the second locomotive reduces the track voltage a bit which also reduces the heating in the problem locomotive.

[buzzard975]

Ahhh, that totally makes sense.   I will give it a little oil and continue to break it in, except maybe I will limit the sessions to 45 minutes or so until I get it fully broken in.  At which point I imagine it would be less likely to bind or provide resistance to the motor?

[Jim Banner]

That is normally the case.  Some motors and power trains are tighter and take longer to break in than others.  But once broken in, these are often the quietest runners.