When I start my 2010 Mazda CX7 Luxury Sports first thing in the morning it blows black smoke out the exhaust for about five to 10 seconds. My dealer told me that this was normal and that all CX7s do the same thing, but is it normal? The other problem I have is when stationary at traffic lights, or when in traffic the car vibrates and idles roughly, and when I take my foot off the brake pedal it stops. Is this a vacuum problem, or is it normal?
Neither problem would seem to be normal and I would be demanding the dealer do something about it. The black smoke would suggest it is running too rich in that first start-up phase, the rough running and stalling would suggest it is too lean once warmed up. I would certainly have it checked by the dealer.