Black soot out of the tailpipe while idling

[atarimike]

Is black soot out of the tailpipe a sign of anything?

I notice when I let the car idle for a while (10 mins or so) I sometimes see black streaks under the tailpipes. Should I be worried?

[GAboySVO]

If it is blowing black smoke, then that would mean an overly rich condition. A light gray would mean a more lean condition. When you start the car, the computer will add fuel during cold starts. This can lead to the black in the tail pipe. In addition, when the engine is cold, you will get water/steam out of the exhaust due to compressing air in the cylinders. The water/vapors mixed with the soot in the tail pipe is most likely the source of your black streaks, especially if you revved the motor.

[atarimike]

If it is blowing black smoke, then that would mean an overly rich condition. A light gray would mean a more lean condition. When you start the car, the computer will add fuel during cold starts. This can lead to the black in the tail pipe. In addition, when the engine is cold, you will get water/steam out of the exhaust due to compressing air in the cylinders. The water/vapors mixed with the soot in the tail pipe is most likely the source of your black streaks, especially if you revved the motor.

No smoke, just some soot coming out. Sounds like it's not a big deal, and I won't worry about it

[svono50]

If it is running over-rich you would have the smell of unburnt fuel too. If no eye tearing and no drop off in fuel economy, then I wouldn't worry too much.