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AliBaba

BMW 7: Engine problems, jerking and smoke - What to do?

Loss of engine power

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Jerking on acceleration

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Check engine light on

I have a BMW 7 and I am experiencing some problems. The check engine light stays on, the car jerks when accelerating and there is a loss of engine power. After accelerating, a drivetrain error message appears, the car then vibrates a lot. When I turn the engine off and on again, the error message disappears. The car falters at low speed and sometimes even white/blue smoke comes out. We scanned the car and got the error message p0430 that the downstream lambda sensor on bank 2 is not working properly. Does anyone have any idea what could be going on and how to fix this?

(Translated from Dutch)

3 comment(s)


Best Answer

CarlyMechanic

The error code P0430 indicates a problem with the catalytic converter's efficiency, which could be due to a faulty oxygen sensor, as your scan suggests. However, the symptoms you're experiencing such as jerking, loss of power, and smoke could also indicate other issues like fuel system problems or ignition system faults. I would recommend starting with the easiest check: replace the downstream oxygen sensor on bank 2. If the problem persists, you may need to inspect the catalytic converter, fuel injectors, and spark plugs. Please remember that these are just suggestions and it's always best to have a professional mechanic inspect your vehicle, especially when safety is a concern. After you've done these checks, could you please update us on the progress? Do you have any other questions?

AliBaba (Author)

Thanks. I have already been to a garage a few times because I smell burnt oil with the smoke and they said it could also be the rubbers on the cylinders melted. But after scanning, it didn't indicate an error code (this was before an error code appeared on my dashboard)

(Translated from Dutch)

CarlyMechanic

@AliBaba

Thanks. I have already been to a garage a few times because I smell burnt oil with the smoke and they said it could also be the rubbers on the cylinders melted. But after scanning, it didn't indicate an error code (this was before an error code appeared on my dashboard)

If you're smelling burnt oil, it could indeed be a sign of a more serious issue like worn or damaged piston rings, valve seals, or even a head gasket failure. These issues can cause oil to leak into the combustion chamber and burn, producing the smoke you're seeing. Given the complexity of these potential issues, I strongly recommend having a professional mechanic perform a compression test and a leak-down test. These tests will help identify if there's a problem with the engine's internal components. Please keep us updated on the situation. Do you have any other questions?

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