Why do I have so much steam coming from exhaust? Seems like every time I start it I get lots of water and steam from exhaust. Is this just a function of cold damp weather?

Are you driving a 914 with an air cooled engine in it? IF so, your engine is doing what it is supposed to do. makes water. It will be steaming when you first start it. After the engine warms up the steam is boiling off before you can see it coming out of the tail pipe. That's my take on it.

Moist air condenses (becomes water) in the your exhuast system when it gets cold. When you start it up, it gets hot and the water comes out both as liquid and steam.

Or it could be from your radiator.

Go to your room

You should sell that steam powered 914 to Jay Leno for big $$$...

Haha thanks for all the replies. I figured it was normal but I dont understand why there would be more steam from air-cooled engine than water cooled

One of the byproducts of combustion is water

Combustion of Fossil Fuels: The combustion of all fossil fuels follows a very similar reaction:

Fuel (any hydrocarbon source) plus oxygen yields
carbon dioxide and water and energy.



The simple combustion reaction below is given for methane. Gasoline is more complex; however, the results are basically the same.

The combustion of methane means that it is possible to burn it. Chemically, this combustion process consists of a reaction between methane and oxygen in the air. When this reaction takes place, the result is carbon dioxide (CO2), water (H2O), and a great deal of energy. The following reaction represents the combustion of methane:


CH4[g] + 2 O2[g] -> CO2[g] + 2 H2O[g] + energy

One molecule of methane, (the [g] referred to above means it is gaseous form), combined with two oxygen molecules, react to form a carbon dioxide molecule, and two water molecules usually given off as steam or water vapor during the reaction and energy.

Did I say something wrong?

Yes, and this is a good reason why you should not drive your car for short little trips. You want your exhaust good and hot when you shut it off to reduce the amount of water in it while sitting.

All cars do this, sometimes I'll see the water pour out of a muffler on a recently started car as they take off from a stop light.

I follow what you are saying and understand how water would accumulate in the exhaust. However, the comment was made that implied that being an air-cooled engine would cause more steam and I am still unsure about how that could be the case.

I just re-read all the threads and no one said there would be more steam from an air cooled engine vs. a water cooled engine. Where do you see that?

I thought that was what he was implying with this statement about air-cooled engine and was curious if I was missing something.

Probably your water pump seal. Or head gasket. Check your heater core. Check your hoses.

Call Auto Atlanta. George will sell you everything you'll need to fix it right up.

Haha, okay thanks! I should probably check that water pump out

Bill, you will become a good teacher.....

Open a course .... first steps im physics and chemistry....take money for that.
Your first customer is known.

And your Exhaust will rust from the Inside out.

If you car is not Concours, you can drill a small hole at the low point of your Muffler & the water will drain out

Hmmm .... install a bleeder valve like the one in the bottom of an air compressor

Check the Fetzer valve on the bypass line... (Name the classic movie)...

Click to view attachment

I like that idea. Almost like installing a drip on a residential gas fuel line.

If you look at most steel, rolled edge mufflers (like an old school style, not like a modern german car), there is usually a small hole in the lowest point on the muffler for a drain.

Great Fletch ref, thanks, BTW.

What cowboy comedy was the other guy in? The guy on the right of course is Chevy Chase.

your favorite .... Brokeback Mountain ...................

Well, he was in a lot of westerns, but he was best in "Blazing Saddles" playing Lyle. His name is Burton Gilliam.