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Why is it that when you start your car up on a cold day there is initially a lot of steam/vapor coming from the exhaust but as the car warms up it disappears?? Is there moisture in the the engine upon start up or something?
Eric....
 

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I would figure there would be water condensation along the inside of the piping.

[This message has been edited by GPR (edited November 15, 2000).]
 

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Discussion Starter #3
yeah, that would make sense... I thought something along those lines... Thanks
 

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My friend is an engineer and I asked him the same question.
According to him, there is some sort of a bag of compound (forgot the name) in the muffler that actually absorbs the left over water vapor in the car's exhaust system when you turn the car off. To prevent rust.
Then, as you turn the car on, the water desorbs (is that the correct verb??) back into the gas stream that passes around the bag of compound. Did that make sense??
I think it's kind of neat
 

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yea... every morning i always get a lot steam... is this right? does this happen to anyone?

thank you
 

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I am not too sure about this, since it has been a while since I had my combustion course but here is my answer.
Every chemical reaction creates 3 major products: Nitrogen, Water, and Carbon Dioxide. My assumption (and I think some professor had actually mention this before) is that when you shut off your car, some of the combustion residue do not flow out of the exhaust system completely and is left somewhere in the system, including water. When you first start up the car in a cold weather, all the parts that the water molecules are attached to are cold, and therefore when the hot exhaust gas pass through the exhaust system, you boil the water and create steam, hence the water steam you see out of the exhaust pipe when you first start the car. Once all the components are up to operating temperature, there are no longer water condensing on the wall of the exhaust system, and therefore, no water to boil and no visible steam (water is now include in all the by product).
 

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i've always wondered about this, and until now i though it was because of the devil. now i know better. whew.

(i sorta like the steam, myself...looks cool coming from dual exhaust)
 
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EricK
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