Foggy exhaust on cold morning starts

[g2tegdave]

Hey guys my 90 teg started to fog really bad out the exhaust on cold morning starts. After it warms up it will go away until the next morning. So what are you thinking?? Valve guide seals or rings?? I didn't pull any of the plugs yet. Any suggestions?? Thanks

[malloyboy1]

haha i was reading this and my buddy was like " tell him every car does that when its cold out"

[lawdogg]

What color is the fog, and what does it smell like?

[The Captain]

I have the same problem. Whenever it gets cold out and i breathe i get fog out of my mouth. I must have a blown valve in my heart or something. Lol, just being a smartass.

[italianblaze]

Originally Posted by malloyboy1

haha i was reading this and my buddy was like " tell him every car does that when its cold out"

lol i thought the same thing with older cars anyway my probe usta do that

[g2tegdave]

Color is white and it smeels like oil

[Kevin]

hahahahaha



Here's my car last winter. Blown valvez all overz.

[Kevin]

Originally Posted by g2tegdave

Color is white and it smeels like oil

It's probably running rich. Do you have a cat?

[g2tegdave]

Yes I have a cat. Could it be the valve guide seals? It only does it sometimes on the first start. After i drive it for a minute it will go away.

[evomike]

Are you kidding me are you 3 years old, have you never seen another car before, they always say there are no dumb questions but come on.

[turbo4g63]

seriously one of the dumbest questions ive ever heard......do you pay attention to other cars? every one of them does it....especially when its cold

[Kevin]

Originally Posted by turbo4g63

seriously one of the dumbest questions ive ever heard......do you pay attention to other cars? every one of them does it....especially when its cold

If it's white like the pic of my car then your fine. If it as bluer and really smelled like true "oil" I'd be worried. Your driving a Honda so I wouldn't worry.

[g2tegdave]

oh well...I have a b16 head here to work on.

[g2tegdave]

Originally Posted by turbo4g63

seriously one of the dumbest questions ive ever heard......do you pay attention to other cars? every one of them does it....especially when its cold

So what you're telling me is that every car lets out a big cloud of white smoke??

[Kevin]

Originally Posted by g2tegdave

So what you're telling me is that every car lets out a big cloud of white smoke??

Pretty much. I know that a friend of mine works for Honda and he told me that their operating temperature is high and that's why they smoke so much when it is cold outside. Something like that.

[evomike]

every car and every living thing smoke in the cold didnt you realize this when you were 2 and building snowmen

[SovXietday]

It's condensation all over the exhaust, it heats up and evaporates it and there's your smoke.

[Raven18940]

Originally Posted by SovXietday

It's condensation all over the exhaust, it heats up and evaporates it and there's your smoke.

^Exactly, you guys could have tried explaining why instead of bitching that it's a stupid question and this thread would have been done in two posts.

Long explanation:

Bascially when you burn gasoline there are two byproducts, carbon dioxide and water (there's other stuff like carbon monoxide and nitrogen oxide which are bad for the environment, but they make up a small percentage of your "waste".) Now, what happens when you put a glass of cold liquid outside on a humid summer day? Condensation. The water vapor in the air is sticking to the glass. So the smoky exhaust you're getting in that same concept, but inverted. The cold glass is your cold exhaust system and the humid air is your exhaust. So the humid exhaust that isn't really hot yet (cause your engine is cold) is hitting the cold exhaust walls and turning into water, but the exhaust keeps coming and adds energy to the water, turning it into steam, which is what you see coming out of your tailpipe. Once everything heats up the exhaust is so hot that it never condenses on the exhaust walls and just blows right out the car.

Now why does it smell weird. What your smelling is unburnt fuel, remember it, it's a good thing to know. This is caused by the cold start rich condition. Again, this is completely normal. The ECU is running rich when the engine is cold because cold fuel doesn't vaporize well so you don't get a good, complete burn. It has to run rich to keep itself from stalling. Once it reaches operating temperature the cold start condition ends and a normal injector pattern is selected.

Any questions, or clarifications?

[g2tegdave]

Originally Posted by Raven18940

^Exactly, you guys could have tried explaining why instead of bitching that it's a stupid question and this thread would have been done in two posts.

Long explanation:

Bascially when you burn gasoline there are two byproducts, carbon dioxide and water (there's other stuff like carbon monoxide and nitrogen oxide which are bad for the environment, but they make up a small percentage of your "waste".) Now, what happens when you put a glass of cold liquid outside on a humid summer day? Condensation. The water vapor in the air is sticking to the glass. So the smoky exhaust you're getting in that same concept, but inverted. The cold glass is your cold exhaust system and the humid air is your exhaust. So the humid exhaust that isn't really hot yet (cause your engine is cold) is hitting the cold exhaust walls and turning into water, but the exhaust keeps coming and adds energy to the water, turning it into steam, which is what you see coming out of your tailpipe. Once everything heats up the exhaust is so hot that it never condenses on the exhaust walls and just blows right out the car.

Now why does it smell weird. What your smelling is unburnt fuel, remember it, it's a good thing to know. This is caused by the cold start rich condition. Again, this is completely normal. The ECU is running rich when the engine is cold because cold fuel doesn't vaporize well so you don't get a good, complete burn. It has to run rich to keep itself from stalling. Once it reaches operating temperature the cold start condition ends and a normal injector pattern is selected.

Any questions, or clarifications?

Thanks alot for clearing that up for me. Appreciate it.

[Kevin]

Thanks Bill Nye.