Greetings, I was hoping for some advice with regards to a brand new 535i with xDrive. I've noticed the left tip on the muffler has a black coating absent on the right tip. On past BMW's I've owned, I'd suspect an issue with the oxygen sensor on the bank feeding that chamber of the exhaust. I have not noticed any smoke of any kind (I followed the car while an associate drove it, at times hard, for me). This car is far more complicated, however, and my first foray into forced induction. I was hoping to get an informed opinion before taking it to New Country BMW in Connecticut (place of purchase). Do you feel this is a cause for concern? If so, do you have any advice on how to approach it to not get it dismissed at the dealer? Thank you for your time!
Probably not a problem. If I am not mistaken, the second pipe has a vacuum controlled butterfly valve that only opens under certain (full throttle or heavy load) conditions. The muffler is fed evenly by all cylinders. That is the way it works on the older cars, anyway.
Oil on exhaust tip I have the same issue with my 2008 535XI. So far, the engine has run fine. I just wipe it off and motor on. Buck Cording 2008 535XI 1973 2002tii
Carbon deposit on exhaust tip Made same query to BMW of Sterling, Virginia service advisor re the exhaust tip on my 535xiT. He echoed the other replies. It is a common occurrence, the way it is. The right tip stays clean because it is not used unless the damper opens. The left experiences build up. But I've never seen that on my '97 M3 twin exhaust tip exhaust, and the 528iT I had, although not a chrome exhaust, never blackened up like the 535. So still puzzling. But the engine is a dream to drive...
