why the tail pipe is dripping water when the car is new

[nismo1003]

What is it actually dripping at the tail pipe? h2o ? what is it actually happing? and why it only happen when the car is new ? If it's from the exhaust gas? wouldn't the Cat block the water already? can anyone tell me?

[180fan]

combustion reactions yield water, in this case vapor which condenses as it reaches out the pipe and comes out as water.

[bangstanger]

Ya ever hear an old lady at the muff shop tryin to tell the guy she only drives on sunday and only 1 mile to church and back and needs a new exhaust every six months? Its not the combustion, but the catalyzation that yields H2O, and CO2 CO etc. well the moisture collects and most of the time is blown out or vaporizes in the exhaust. Especially with new cars with good catalysts, you get a higher concentration of moisture and can see it "drip" from the pipe. The one best thing you can do is to make sure that if you are only taking short trips (not the 1320) that you let the car warm up a bit and tap the gas a little a few times when you get back. That will help to blow out some of the moisture. Other than that...dont worry .. its perfectly normal for todays super governed atmosphere friendly cars.

Carl( 4 yrs in a muff shop talkin)

[navysnail]

that old lady has the same condensation problems inside her engine too, in the form of sludge.

and yeah, nothng to worry about, in winter all that vapor that is visible is the water that is evaporating and not dripping, so it does release a considerable ammount of H2O

[DAEDALUS]

It has nothing to do with the catalytic converter. Purely a combustion product, like 180fan said. Short drives don't allow the water to boil off, so it just accumulates. I have the same problem--work is only 3 miles away.

[bangstanger]

DAEDALUS? Do you know what the composition of the exhaust gas is when its burnt...thats what the converter does...converts it into H2O and CO2 and CO and other little chemicals that arent as harmful...

But I would love to know more if you do know. I am not being rude... I would truly like to hear what you have to say. If you would like .. email me so we dont steal this thread.

[email protected]

[DAEDALUS]

We can post here--that's what this board is for!

I take back my statement it has *nothing* to do with the cat. I will restate, it has *very little* to do with the cat. The combustion gasses that leave the cylinder (before they enter the exhaust pipe) are already CO2 and H2O (ideally). The only thing is that combustion is usually not 100%. On a decently running engine, on the order of 3% of the gasoline (HC) and air do not mix right and thus do not burn in the cylinder. The cat is a hot surface that allows these 2 ingredients to meet up and burn, thus reducing HC emissions.So, about 97% of the H2O is formed before the cat, and about 3% at the cat. In a perfect, theoretical engine, no water would be formed at the cat. (In a perfect theoretical engine you wouldn't need a cat anyway).But really, this burning of HC is still a form of combustion, just on a hot metal surface. Catalyzation is the conversion of bad stuff to not-so-bad stuff using noble metals (platinum and palladium). Specifically, in this case it's the oxidation of CO (deadly) and O2 into CO2 and, in modern cars, also the reduction of NOx (smog) and CO into N2 and CO2.

[180fan]

http://www.elmhurst.edu/~chm/v....html

that should walk you through it somewhat. Gasoline is a hydrocarbon fuel.

[bangstanger]

Well thank you... I guess I was misinformed all these years. I never bothered to look into since it made sense. Business sense I guess..lol..It it always nice to learn something new, especially when you finally get the right info. And I guess I should appologize 180FAN if I stepped on your toes then.

Carl

[180fan]

nah think nothin' of it.