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Discussion Starter #1
Small puff of dark smoke out the tail pipe in the morning! What could this mean?[???:)]
 

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I am not EXACTLY sure... but I think your car may be running kinda lean... On Diesels when they gun it and the black smoke pours outta the tailpipe that is burnt fuel... I pretty sure it would be the same for gas engines.
 

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could mean a low qaulity fuel, black smoke = carbon or really rich mixture..!!!

i would suggest filling up somewhere different
 

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How many miles on the car?
 

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Discussion Starter #5
No smoke this morning!
 

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i get smoke every once in a while when i step on it hard. but itdoes not looks like there is a problem with my car.

in fact, if i go to the car and rev it to 7krpm after the rpms go down i'll get some smoke.
 

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Depends on the smoke !! Smoke with a blue tint on a high milage engine, may be oil coming past the rings. On start-up it could be oil seeping past the valve guides.
If it is just gray smoke, it is some unburned fuel.

If it has a white wispy appearance it ( this is the most likely ) is water vapor that has collected in the exhaust overnight from condensation.
 

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Discussion Starter #8
viney266 said:
Depends on the smoke !! Smoke with a blue tint on a high milage engine, may be oil coming past the rings. On start-up it could be oil seeping past the valve guides.
If it is just gray smoke, it is some unburned fuel.

If it has a white wispy appearance it ( this is the most likely ) is water vapor that has collected in the exhaust overnight from condensation.
What would cause oil to get past the valve guides?
 

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worn guides
 

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Discussion Starter #10
HempHound said:
worn guides
what are valve guides and how would they become worn on a car taht has only 20,000 Km on it?
 

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Discussion Starter #14
WickedlyFastST said:
I know...LOL
LOL. Anyway, isn't it true that are cars fuil mixture is controlled by the two O2 sensors in the exhaust header, one before and after the cat? I mean unless you get a bad sensor how would the car ever run anything but a close to perfect mixture?
 

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(fires up a hooter)

The car is fine.

Black sooty smoke like a diesel is just a minor fuel issue, and it went away- so only a temporary issue. Who knows, maybe you tapped the accelerator when you started the car and since you're in open loop mode at start up- the O2 sensors aren't correcting anything so you had a lean condition for a few seconds. Like Y2KPedo said, he notices it when his car accelerates hard sometimes- it's just a temporary lean condition. If you had a 2nd cat- it's likely you wouldn't have seen it.

Valve guides can be worn at 20k miles, but unlikely unless you ran it without oil, and we know there would be other issues. Viney described it well- grayish blue smoke is oil smoke from whatever condition- not black sooty smoke.
 

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WickedlyFastST said:
I am not EXACTLY sure... but I think your car may be running kinda lean... On Diesels when they gun it and the black smoke pours outta the tailpipe that is burnt fuel... I pretty sure it would be the same for gas engines.
running lean would be a puff of white smoke or condensation coolant it could be alot of stuff...get it checked.
 
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