F430 Condensation

Water coming from the exhaust of a catalytic-converter-equipped car typically indicates that your air/fuel mixture is too rich.

If you like to shift gears at very low RPMs (e.g. below 5000), then it is probably nothing to worry about.

 

but with my 360. I usually start it and let it idle in the garage to warm up a bit before I take is out, and there's usually a small puddle (like 4" in diameter) below each side. I just had a major done (belts, all fluids, etc) and while I didn't highlight that issue, my dealer didn't raise any concerns. Not that that means a whole heck of a lot...but I felt that they were very thorough in their service.

 

Most any vehicle will drip water from the exhaust when cold. Water is a byproduct of combustion and a cold exhaust system will allow it condense. It has nothing to do with fuel mixtures. My 430 has done the same thing since day one (8/05). It is wise to clean the paint beneath regularly.

Dave

 

Mine is the same as well . Almost all cars do this to some extent .

 

When I was at the Ferrari Service Center in Orange County, CA I saw a gang load of 360's and 430's with black marks/soot covering the paint around the tailpipe area. It seems like this is a combo of the condensation coming out the tailpipes and black smoke? Not sure.

Didn't notice any build up on my F430 but I try and keep it pretty clean.

 

Normal. This is why one should never short trip a car and always get fluids up to temp. Signs of short tripping is milkey oil filler cap.

 

Rich mixtures produce more water vapor. Rich mixtures also tend to lead to cooler exhaust temps. The combination of more water vapor with cooler exhaust temps can cause more water vapor to condensate into liquid water (gasseous state to liquid state).

Same goes for cooler climate and a car that's run before it is up to temp, as the cooler exhaust system will condensate more water than will a hot exhaust.

This is why you see some, but not all cars, and not all cars at all times, dripping water from their exhausts.

 

The amount of water produced from combustion of hydrocarbons is a fixed chemical reaction that has nothing to do with mixtures. If anything, a rich mixture just sends unburnt HC's through the exhaust that never have a chance to be turned into water and CO2, so a gallon of gas in a car running rich would actually produce LESS water than a gallon of gas burned in a more efficiently running motor.

Methane combustion= 1 atom of methane CH4 + 2 atoms of oxygen O2 = 1 atom of CO2 plus 2 atoms of water H2O. Gasoline and the atmosphere are more complicated which is why you get unwanted byproducts like CO and Nx compounds but the basic chemistry is the same.

Dave

 

That would be true if each combustion charge was 100% consumed, but in reality the efficiency is less. Increasing the richness isn't more efficeint, but it does add to the total being combusted. This is why making a car richer above the stoichimoetric ratio can increase power in some instances.

Likewise, making it richer can increase the water vapor being created.

Moreover, running richer means a cooler exhaust for a longer amount of time, and it is that cooler temperature that allows more water vapor to liquidize.

Thus, a rich mixture increases visible water out of your exhaust pipes in two ways (temperatures and volume).

 

False, in "perfect" combustion (stoichiometry) H2O and CO2 are the only products (petrol is a hydrocarbon). If running rich, CO would be high, leaving carbon deposits around the pipe and/or bumper. Condensation is usually caused by taking many short trips, if the exhaust doesn't get hot enough to vaporize the water on contact (with the pipe) the water builds up. Only way I can think of to prevent it is to make sure that every trip you take the car reaches full operating temperature, as does the exhaust. Other than that, it just means combustion is efficient. Consider it a blessing in disguise.

 

Tom, just do me a favor and call me the first time that you see a car running lean dripping water from its exhaust. I want to see it.

 

Making the mixture richer just forms more byproducts of incomplete combustion out the exhaust i.e. HC's, CO, Nx's, C, etc., not necessarily water. Additionally the presence of HC's in the exhaust will make the cat heat up quicker causing condensation to end sooner, not later.

Dave

 

I get a bit of milky oil in upper filler cap after a nice, hot, long run...begin to think it might be a bit of water in oil.

couldn't this be a sign of such too?

 

Making the mixture richer won't make the combustion more complete or more efficient, but it will make more mixture combust. That's why you get more power with a richer 11.2 air to fuel ratio than with a leaner 12.5 to 12.7 stoichiometric ratio.

By that token, a stoich (or even lean) mixture would cause more water to condensate from vapor and drip out an exhaust.

Thus, you'd have more water dripping from non-cat car exhausts with a rich mixture, but more water with a lean mixture from cat-equipped cars based on your above.

 

Actually, I think the amount of water that drips out a tail pipe is more a function of the exhaust system design and the motor size than anything else. Everything else would have a minute effect either way.

Dave

 

Did I say "lean mixtures" would cause more water? I said the closer to stoichiometric, the more H2O. Going rich can increase CO/HC, and going lean can increase O2/NOx/HC. In both cases CO2 decreases, as does H2O. Please don't misinterpret my statements, going lean will not increase condensation. I never said that and never will. I've spent the last 6 weeks, 5 days a week, 6 hours a day, in a classroom learning about drivability and emissions. I surely know what gases come out of a tailpipe, I promise.

 

OK. I'll defer to your current schooling. Close to perfect stoich (lean for a performance car, by the way) mixture produces the most visible water (i.e. in liquid rather than vapor form) dripping from a cold tailpipe.

Case closed.

 

Sorry, didn't mean to make a whole big deal of it... I'm not here looking for an argument. Either way, I think we all agree condensation at the tailpipe is nothing to worry about, and if you make sure the car gets to standard operating temp it can prevent it. Problem solved.

 

Sir, Does this mean Anne Margarettes not coming?

 

+1 it is actually a good thing if the car has just been started .

This is true!!!

 

don't worry, be happy! Its all good...