- Clogged air filter element (chapter 1).
- Injector malfunction (chapter 4).
- Incorrect ignition timing/ignition system malfunction (chapters 1 and 5).
- Insufficient tire pressure ("Weekly check").
Fuel leak and/or fuel smell
- Damage or corrosion of the fuel tank, lines or connections (chapter 4)
Excessive noise or soot from the exhaust system
- Leak in the exhaust system or manifold connections (chapter 4).
- Leaking through a rusty or damaged muffler or pipes (chapter 4).
- Contact of the exhaust pipe with the underbody or suspension due to damage to the exhaust system mount (chapter 1).
The original text of the article is available on the resource: BMWMan