More Black Smoke than "Normal"

[johnbrowder]

Janene and I are on a 6 week western US trip that is scheduled to end up in Austin at POG. We have logged about 3500 miles and things are going well. I have noticed recently that on acceleration (or even kicking on high idle) I see a brief puff black smoke from the exhaust. There has always been a little, I would guess it is twice as much now. I never recall seeing ANY when turning on high idle. It still only last a second or so.

We have been in cooler temps, less humidity, and higher elevations than routine. No engine fault codes, and no change in mileage.

Should I be concerned?

[grantracy]

I had the same problem and went to a DD service facility, turns out defective injectors were the culprit. Also discovered hardware for Jake brake was broken...don't know if the two were related...anyway that was my experience.

[Jon Wehrenberg]

John,

When you get back to lower elevations see if it has gone away before considering remediation. I know DDEC is supposed to compensate for loss of boost due to altitude, but that might be normal.

[Larry W]

John
We live at 6000 ft above sea level. Our bus puts out more black smoke when starting from a stop or when I really ask for power with my heavy right foot. At lower elevations the smoke is a lot less. There is just not as much air at higher elevations. At 10,00 feet is is not possible to see 30 pounds of turbo boost. We are currently on the return leg of a trip of about 6000 miles. Here at 1200 feet there is very little smoke and it is easy to see 30 pounds of turbo boost. As Jon advised check all when you are at lower elevation.

[johnbrowder]

OK, if Jon W says it, I buy it! Plus, that's what I really wanted to hear. By the time we get to TX we will be back at "normal" elevations, and I should have a pretty good idea if smoke is back to baseline. I will try to post a followup.

[AmeriStar]

You might consider changing your air filter. Most people neglect this simple but important change.