I have a new Hyundai Accent, just broke 5000 miles. It is now spitting black watery soot out the tail pipe. inside of the tail pipe is """"CAKED!" with black soot. {I have a plymouth neon with 250,000 miles on it and barely turns my finger black if I wipe the tailpipe} I have also noticed that when I turn my vent on, it literally smells like a filthy dirty sock, even my husband said, "thats not right! also seems that when driving, especially when I take off the car seems to hesitate or slip. Are these things connected to one problem? Also, after about 3 minutes of the car spitting crap out, faint white smoke begans to come out.

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    This is a new car, so take it back to the dealer. There is something wrong. If you start messing with stuff to fix this issue, you could void your warranty.
    – CharlieRB
    Commented Feb 21, 2017 at 12:20

3 Answers 3


Check for an inoperational EGR system

Things like a stuck EGR valve or disconnected/damaged EGR hose could explain the sooty exhaust, fumes in the cabin and apparent stumbling.

Exhaust Gas Recirculation acts by resending a portion of the exhaust gas back to the combustion chamber. If it is inactive there will be more soot in the exhaust.

If there are exhaust fumes in the engine bay, this will impact cabin air quality.

If the EGR hose is somehow sucking in fresh air instead of recirculated exhaust gases, this will affect affect the fuel trims and may induce hesitation/stumbling under load.


Faint, white smoke in the exhaust is oil. Your car is burning motor oil. Check the dipstick to see if the oil level is low.

There are a couple of possible reasons why the car is burning oil, none of which can easily be corrected.


All engines will create some soot, but it is usually unnoticeable. Excessive soot, is an indication there is something wrong, especially on a new car.

There are two likely causes for this.

  1. Un-burned fuel - there may be something wrong with the fuel injection system causing it to run very rich and the engine is not able to burn all the fuel going into it. This would be soot with smell of fuel.
  2. Oil is getting into the exhaust - in this case, you would see blueish smoke while the engine is running. The soot would have a oil feel and would smell of burned oil.

Since you are seeing faint white smoke, I would suggest the fuel is not being burned completely. This can be caused by a cylinder not firing, a fuel injector stuck open, a faulty sensor telling the computer the engine is lean, etc.

You need to take it to the dealer and let them diagnose and repair this under warranty.

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