Exhaust 'spray' on start up.

Greetings All,
I have just received my 2010 A4B8 2.0LT Quattro ( still in love), 1060 Klms on the clock.
Any idea what the ' black soot like substance with water, possible condensate', from the exhaust might be ??.
Each time I start the car I seem to leave this 'spray' of substance on the driveway.
Persistent hosing will remove the substance, but I would like to know just what it may be.
Best Regards and thank you in advance.
John

See what happens the the boss pressures you to send an email.

The car is petrol not diesel.

might just be old crap sitting in the exhaust from when the car was sitting around prior to being owned by you.

I think you need to drive it hard and give it a good spanking, do you do only short journeys?

thanks

Carbon combustion residue mixed with water vapour condensate from the fuel and the air.

Hi Johnvw,

I can only guess as for an answer but just so you know ...

My B8 2.0TFSI does exactly what you have described, and even after 30,000km it continues to leave a wet sooty streak on the garage floor. The majority of my use is for long trips so it isn't due to 'short trip' water condensation/carbon build up.

I do note that on cold start up, for about 30 sec, the engine idles very fast which I understand pre-heats the exhaust catalytic converter. My guess is that this is a very rich fuel mixture which creates the excess spray out the back.