Smoky vehicles

Fix your smoky vehicle

Smoky exhausts increase air pollution. If your vehicle emits excessive smoke, check the cause and service or repair your vehicle.

Maintaining diesel engines

Diesel engines shouldn't emit continuous smoke if maintained properly, driven carefully and fuelled with quality diesel.

What causes vehicle smoke?

Several factors contribute to vehicle smoke, including:

  • how the car is serviced
  • how the car is driven
  • engine wear
  • fuel quality
  • engine design
  • pollution control equipment
  • journey length.

Even well-maintained vehicles might emit visible smoke when under maximum power, during gear changes, while carrying heavy loads, or after idling.

Continuous smoke warning

If your vehicle produces smoke continuously for 10 seconds or more, this means that something is wrong and needs fixing as soon as possible.

Types of smoke

Vehicle smoke usually results from unburnt or partly burnt fuel. Burning engine oil can also lead to smoky exhaust.

  • Black smoke: Typically results from incompletely burnt diesel fuel.
  • Blue, white, and other coloured smoke: These colours usually signal burning engine oil or unburnt fuel vapour. Blue smoke, in particular, often points to a serious engine issue.

Common smoke causes

Various faults can cause smoke, affecting both petrol and diesel engines differently. These include:

  • overfilled engine sump
  • blocked air cleaner
  • faulty cold start fuel enrichment systems
  • damaged electronic or mechanical controls
  • contaminated or improper fuel
  • blocked or damaged fuel filter
  • incorrectly set or damaged fuel injectors or pumps
  • worn engine components such as piston rings, pistons, or cylinder bores
  • incorrectly set or damaged turbochargers or superchargers

Take Action Against Pollution

Smoky vehicles significantly contribute to air pollution. If you notice a vehicle emitting smoke for 10 seconds or more, please report it.

Report a smoky vehicle

If you see a light vehicle blowing smoke continuously for 10 seconds, you can report a smoky vehicle online.

If you see a heavy vehicle (gross vehicle mass of more than 4.5 tonne) blowing smoke continuously for 10 seconds, you can report the vehicle to the National Heavy Regulator (NHVR) on 13 64 87.

You will need to report the vehicle's make, model, colour and registration, and the time, date and location of the sighting.

You can only report vehicles with Queensland number plates and exhausts that smoke continuously for 10 seconds or more.

What happens once you report the smoky vehicle?

The reported registration number is compared with the reported description to make sure they match. If they do, a letter is sent to the owner explaining that the vehicle has been reported and suggesting ways to fix the problem. If the vehicle is reported 3 times within 4 months of the first sighting, the owner is issued with a Present Vehicle Order for the vehicle to be checked for defects by a transport inspector.

Usually, a simple service is all it takes to fix the problem. More than 80% of people report they fix their vehicles as soon as they receive the first letter. Owners have 1 month to fix the fault and return a form explaining what has been done.