Hi Scotty,
got a 2012 bmw 740li with 185k. In-line six twin turbo motor. I have owned the car for the last 120,000 miles and around 155,000 miles the following problem began. When I accelerate with any degree of urgency around 20-40mph I get a “powertrain malfunction” on screen. I ran the code and it was low boost. If I drive in a spirited fashion when I come to a stop I get smoke coming out of the right side of the hood by the windshield and the front grill and under the wheel well. I am told this is due to a turbo failing with a wastegate problem on the passenger side of the engine. What is the smoke coming from? Is that oil boiling off that is used to cool the turbo? This has been going on for 30,000 miles and now in the last 2000 miles I am getting low coolant which I have topped off and within 2 to 5 miles I am getting low coolant again each time. If I drive like a boring person, I get no powertrain malfunction and no smoke but still have coolant problem as of late.
I put a new transmission in the vehicle at 150,000 and that has been flawless ever since.
thanks for your help!
You're going to need to replace the turbos. Definitely one, likely both. And having driven it over 30k miles in this condition, I would expect more damage to be found with the engine.
German cars are not Honda Civics. They HAVE to be meticulously maintained or you will have never ending problems out of them that will cost you tons of money. You bought a 7-Series, their flagship car, and haven't maintained it properly.
If I were you, I would look for another vehicle because I've seen these things before on 7-series and other BMW's and you've got a four to five digit repair bill coming to get it repaired correctly.
Exactly what I thought!
Unless you’re the type of person who doesn’t mind diving into the moneypit, get rid of that thing ASAP.
At a minimum you’re looking at a new turbo. But to get an accurate diagnosis, you’ll need to visit a specialist BMW shop with people who know what they’re doing. And at that age (approaching 10yrs), there may be a whole lot of other plastic components which might snap & break and only add to your repair bill.
Again, get rid of that thing and if you’re smitten by the 7 series, go find another one that’s running good and doesn’t have any of these issues.
