Why does water come out of my exhaust?

360 spider, Capristo stage-3......

When the car is first started-up, water can be observed ever-so-slightly being blown out the rear of the exhaust pipes....just a hint and for just a while. I know it's not coolant and I've seen this before on other cars....but what the heck causes it and is there any cause for concern????

 

I dont know why its there but i think it happens to every car
EDIT: conensation I think is the answer

 

warm/hot air can hold X amount of moisture as a gas (vapor)....when it cools down it holds less moisture as vapor....the "left over" moisture becomes apparent as liquid (as opposed to its vapor form in the wamer air) assuming many variables but this is the gist of why condensation occurs.

so as hot gasses that contain water vapor leave the engine and become cooler (throughout the exhaust system) some of the water vapor becomes liquid. its the same concept of why we see our breath on cold days.

EDIT:
most likely happens during start up because the exhaust pipes are still cold, while the combusted gasses in the engine are very hot....once the car has been running the exhaust temp increases so doesnt cool down the gasses as much

 

its just steam,cause the car is starting to warm up,its just natural

if i'm wrong,please correct me,thanks

 

air conditioning.

 

Out of the exhaust?

 

werd. every healthy running car whether it be a civic or a fcar has condensation dripping out of exhaust during warmup

 

It's peeing in the morning, just like us.

 

Ideal combustion of a hydrocarbon (gasoline in this case) produces carbon dioxide and water. If I remember correctly, combustion of a gallon of gasoline will produce approximately one gallon of water. When the exhaust system is cold, this water which is normally in an invisible vapor form condenses and appears as steam or actual liquid dripping from the exhaust system. A good reason to always get your engine (and exhaust system) to operating temperature before shutting down again. This will ensure that there isn't any water remaining in the exhaust system to rust it from the inside out.

 

Alrighty then......good deal. I was terrified someone was going to say that "if this is happening on your 360, get it to a dealer immediately and bring an extra $24,000"

Yes, it's normal and it's just moisture & condensation. The reason it happens on some cars more then others is simply the nature of the exhaust sytem. My stock 355 doesn't do it so much due to the length, design and lay-out of the exhaust pipes....hardly anything comes out.

While my 360 with it's Capristo stage-3 has a pipe configuration that allows it to blow-out the water quicker and in more volume.

All is well, all is good....let's return to our regularly scheduled F-chat chat-chat

 

Related to your question, I was advised by muffler specialists that its important to drive one's car enough, after start up, to burn off the water vapor. Otherwise, it sits in the exhaust pipes, contributing to erosion or rust. Whether this is true or not, it has influenced me over the years NOT to just start up my Fcars for a short idle or spin around the block and then turn off the engine, but to really heat the entire engine/emission system up via a good run before returning the car to the stable.

 

water is produced as a byproduct of the exhaust gases going through the cat and being broken down - if I recall correctly. Or your head gasket is blown

Here is a very good technical write up on the process:

http://hyper-flow.com/technical.htm

Check your radiator coolant (use caution of course and do it when it's cool) for oil/foam on the surface just to be sure. I suspect it's pretty normal though.

Ray

 

Have the area right below the exhaust covered with 3M clear film. I did, no more mess on my F430. The black water stuff runs right off & won't stain your paint!

 

This is what I was always told, hence why people who just do very short journeys replace exhausts quicker due to this