Since winter is here I have been starting my Mini on the cold mornings and letting it run/warm up for a few minutes before leaving the house. I am pretty sure what I am seeing is normal but wanted to check and get an explanation of why...

Since doing so I have noticed condensation and dripping water comes out the exhaust tips. The tiny puddle that it leaves is black and I assume its from carbon/soot (sp?) from burning fuel.

Can someone explain and confirm this?

 

Yep - it's normal. Water is one of the normal combustion byproducts from the catalytic converter. Cold air can't hold as much water vapor as hot air (that's why hot/humid days are more common than cold/humid days). When the hot exhaust hits the cold outside air, the water vapor in the exhaust condenses out into liquid water. It does it all the time, but more so when it's cold outside.

And the black in the water is coming from the soot, as you supposed.

Scott

 

Yep, AND when you first start up the car the exhaust system is cold. The cold exhaust tubing acts just like the condensing coil in a a still. It condenses the water vapor back into a liquid...which runs through a sooty tube and drips out!

Rawhyde

 

this is normal and one of the main reasons why i don't like
starting the car just to move it around so that i can make
room to work on another car.

 

Yet another reason why it's *not* a good idea to periodically start the engine on a car that's in storage just to let it run for a few minutes. You get water condensing in the exhaust tubing, and then if you shut the engine back off before the exhaust has gotten fully heated up, the condensed water just sits in the exhaust and slowly rusts everything out.

Scott

 

I noticed this tonight... but im getting a gurgling sound if its in neutral and i rev the RPM's up to 3000 real quick and let off the throttle...

Now is that normal??? or should i take my MINI in to the shop.. I just got it 2 weeks ago...

thanks,
Allen

 

That's the normal MCS "Burble". You can do a search for it here on the site. It sounds even better when you're shifting under acceleration.

 

All cars do this, some worst than others. The MCS is a bit worse than others because of it's ;ong exhaust system past the catalytic converter which also passes through a large muffler and then a large resonator. Lost of cold surface area to deal with. In fact, if you start the car and let it idle on a cold, below-freezing day, the exhaust will never get beyond lukewarm to the touch.

 

well i hope this is ok... it's more like a:

step on the gas in neutral and vrooooooooooooooommm blugh blugh......
but it only happens in neutral when revved and sometimes when shifting to 2nd gear coming out of 1st gear..

Does that sound like the same thing... i really dont like this gurgle sound... it sounds like a leak in the exhaust or something... but water does spit out...

Allen

 

I don't think I would describe the burble as "blugh blugh" - it's more of a rapid popping/crackling sound, like you hear on racecars when they decelerate. Most people that hear it, like it, so you may be describing something else. Best to take it to the dealer and ask someone there if you're worried about it.

Scott

 

Exactly... you create water everywhere... which also mixes with the oil...etc... Must run the engine long enough to burn off water in all areas..

 

yesterday night i was behind a modded WRX and saw a fireworks show
from his exhaust tip. kinda cool. he wasn't racing or anything either,
just a hair faster than normal acceleration.