Black smoke from the exhaust
Black smoke is unburned fuel: the engine is running rich. It is common on diesels under hard acceleration if something is wrong with air supply or injection.
AreaExhaust & smells
UrgencyModerate
Can I keep driving? Drivable with care. Diagnose soon: performance, economy or other components can be affected.
Common causes
Clogged air filter
Not enough air for the fuel.
Faulty MAF sensor
Incorrect air measurement.
Leaking or worn injectors
Too much fuel, or poor atomisation.
Boost leak or turbo fault (diesel)
Not enough air under load.
EGR stuck open
Exhaust gas displaces fresh air.
What to check
- Check the air filter.
- Read fault codes, especially fuel trim, MAF and boost codes.
- Check for boost leaks on turbo engines.
- Have injectors tested.
Related OBD2 codes
Repair guides
Other exhaust & smells problems
General guidance only. A qualified technician can confirm the cause; brakes, steering and fuel leaks should be checked professionally if in doubt.