LEGACY #5409 K4 NEW FEATURE ?

It'll go away, I think it may be a little oil, but I'm not sure.  I've seen it on several, nothing to worry about.

I've seen it as well, I almost wonder if it isn't some dust from dry graphite used at the factory. The electrocoupler doesn't get hot so it doesn't seem like it would be smoke.

I agree with John, nothing to worry about.

Swinging Whistle, coupler-steam, this engine has it all!

I noticed it yesterday when I put it on the track for the first time.  Also, can someone tell me how many drops of smoke fluid go into the whistle hole?  I didn't find this in the manual or is this smoke unit set up with the smoke stack.  It does have two switches under the cab so I presume it has its own unit?

I thought Lionel may have omitted the whistle steam on these K4s, its not in the description.

If it indeed does have it.Lionel released an addendum for filling the smoke unit, they forgot to ad the instructions to the manual. The fluid DOES NOT go in the whistle hole.

FWIW when it comes to filling. The whistle smoke unit is the same type as the stack unit, its pretty thirsty

K4 smoke whistle steam instructions.

Thanks RICK for the info.  I went to Lionel page and found the addendum.