One of the workhorses of my layout is a BR216. It is neither ancient nor modern. It originated from start set 29845 and I picked it up (new???) on EBay from Keesmarklin a couple of years back. It has always been the nice heavy track testing /cleaning lok on call first in most situations. A couple of months ago it was playing up, so some maintenance - new brushes, drop of oil and push and prod with tweezers - and it was back purring round the layout like an old coffee grinder again. Currently relocating my layout so no running for the last two weeks but have got to the point of test running, so call for the 216. When powered on she will move a foot, stop a few seconds move another foot and etc. Same in both directions. To check my track laying another lok was used which works perfectly.

Any suggestions?

With the body shell removed, Run the Lok until it stalls. With track voltage up,Take a wooden tooth pic and touch the brushes to check spring tension. If the Lok starts to run this is where the trouble is. If not, keep exploring and poking round till she starts up.
Low teck at it's best but I have found many a problem this way.

Mikey

Thanks guys for your help.

Stripped down the motor -I know most of you do six of these before breakfast but to me this was a first!. Discovered a lot of gooey black stuff inside cleaned it all up with WD40 reassembled and off she went lovely. I wouldn't have said I was a loco oil maniac but clearly I must be!