Audi q7 black smoke coming out of exhaust
The reason my audi q7 had heavy smoke was because the diesel fuel injectors were dripping which can be checked by means of a leak test, this was caused by the fuel injection pump depositing micro shreads of metal in to the injectors, 5 of which failed.
If you're problem is the same, you will find that the problem occurs when the engine is hot, when the engine has been ticking over for a short period and then you hit the accelerator the heavy smoke is the excess fuel burning off, equally if the idle period is longer you will notice smoke in you're rear view mirror. Audi are well aware of the common engine faults, proof being in the 3 years or 60000 mile warranty, the only top motor brand that don't offer 3 years unlimited ( Bmw, Merc, lexus, hell kia & hyundi have more confidence), you may think I have been unlucky and landed a bad one, I bought a second one as i thought the same which low and behold i had full injector replacement and £1800 turbo fault. each car developed the faults between 63000 & 77000 miles, if you buy a second hand diesel audi with a 3.0 engine or above you are buying the name not reliability which is proof when you look up audi's on autotrader, there isn't many with more than 150000 miles, the same can't be said about BMW & MERC which have there cars with 250000 plus.
