Lionel BNSF ES44AC #6411 and #6425 smoke units stop producing smoke: #1933281 and #1933282.

The only thing that springs to my mind is that the smoke fluid has saturated the wicking and needs some time to get up to the right temp. You don't mention getting any cab light blinks so I assume there isn't one of the faults the system is meant to detect. Other than that, what settings are you using? If these have the same smoke units as previous ES44AC models of fairly recent vintage, they are fairly sensitive and respond to the EFX settings. 

Have you tried gently blowing down the stacks? Diesels are particularly susceptible to having fluid trapped in the outlet by an air pocket.

See Rick's solution, that's likely your problem.

Rick and John,  I did the basic clearing of fluid blockage. I have the previous CSX, SF, NS and BNSF Golden swoosh, and UP ES44AC engines. Blowing air down the stack is always my first remedy, but it did not work in this case.

Hancock52,  The EFX increase in engine load did cause an increase in smoke output when the engine smoked. I stopped using it because it caused the dining car in the consist brakes to squeal.  There were no cab blinks.  I turned the #6425 engine over, but no excess fluid came out of the stack.  How long should it take the heating element to create smoke?. 

Gunrunner John,  Any idea on the type of wick Lionel is currently using?  I have had the cut cubes pull up off the bottom of the smoke units, therefore they were above the fluid that settled in the bottom.  I had to stretch out the layered cube material until it touched the bottom and the heating element on top. The engines are brand new so there should not be burnt scarred wick material yet.  These engines shipped in the bitter cold if that could cause an issue.

I also noted that both engines have paint scraped off the sunshades on one corner, a minor cosmetic issue, but always annoying on a new engine.

Thank you for your input.

Sincerely, John Rowlen

I think Lionel uses cubes of felt-like material cut to shape for factory assembly.  I'm sure that's more a convenience for quick assembly than to optimize smoke performance.

Can you feel air coming out the stack?  Can you feel any heat?  I normally stick my lip right above the stack to try to see what's happening, it's a very sensitive area and you can feel the air and the heat if it's happening.

John,  Thank you for the fast response.  If it is the cube, then I should be able to gently pull it apart like a biscuit in connected layers.  This is what I did with my five Erie FA engines.  Once I did it, the engines fogged the room with smoke.

I sense some slight heat and maybe air, unless fluid is blocking the fan circulation. I guess it is time for Doctor Rowlen to operate. I will put new batteries in my headlamp I wear when working on painting Presier people for my passenger cars. 

I have time tonight to work, since Mom is already sleeping and the cleaning and remodeling is done for the day.  I still have to check the two YLB batteries. Getting the house ready for Christmas took priority.  Family is arriving on the 26th.

Thank you again.

Sincerely, John Rowlen

Yep, I've been slowed up by a lot of family commitments, but things are moving.  I also have to grease the runners on my sleigh and check if I can get down the chimney.

The simple solution is generally better and I thought that clearing the smoke outlet of any fluid blockage might be your answer. If not, then moving on:

1.  The cube or pre-cut wicking is no longer available as a replacement part and has not been for a few years. I agree it probably made for quicker assembly at the factory. It's been a while since I had a brand new Lionel engine where I had to disassemble the smoke unit so I don't know if the factory is still installing it from old stock. Rope wicking generally works better. There's a video by LaidOffSick called "120 drops of smoke fluid" that gives a better explanation than I can.

2.  I have found that it can take some minutes running before later Legacy smoke units get up to max output after the fluid has been refilled. I've been fooled into thinking a smoke unit is defective by not being patient while it warms up. In fact, they have always returned to regular output. 

3.  I have also found that there is also a sweet spot where the combination of the amount of fluid, smoke unit settings and (just as if not more important) good power supply to the track yields the best results. 

What I don't know for sure is how smoke units equipped with thermistors react to different levels of saturation of the wicking. A thread a while back recorded that (per Jon Z.) it's the fluid that conducts the heat to the thermistor. There's no parts diagrams for these engines yet so I don't know if the smoke units have thermistors. 

John, Rick and Hancock52,  Thank you for your suggestions.

I opened the smoke unit on the Lionel 1933282 BNSF ES44AC #6425 and found the new wick material shown in my pictures.  The wick appeared to be dry, though there was fluid on the top of the smoke unit and around the gasket between the top and bottom of the unit.

The wick batting material may have been obstructing the lower intake on the fan unit. Laid of Sick may be correct. I put at least 60 drops of smoke fluid to prime the unit operating in my video in this post.

After rolling the wick in top to bottom coils and re-inserting it into the fluid chamber, I used a screw driver to push the wick material away from the fan opening in the fluid chamber. Now there is no obstruction to the opening under the fan and air flows freely through the smoke unit. 

When opening the ES44AC be aware that there are lifter washers between the body shell posts and the chassis floor. There are eight screws holding the shell on the chassis.  It was easy to open the engine with the cab to my right. I then laid the shell behind the chassis. The wire connections were just long enough to allow this movement.

I will add more smoke fluid to the other BNSF #6411 that stopped smoking, before I open it. Perhaps low fluid may be the cause of it not smoking.  The ES44AC smoke chamber is large enough for 60 drops of fluid.  There was some browning to the wick material starting on the #6425.

Note: I turned down the sound on the engine because family members were sleeping.

Again, thank you for your comments. I appreciate it.

Sincerely, John Rowlen

Lookin' good, glad it was an "at home" repair.