There are many signs and indications that a car is not working as it should be. Strange noises, vibrations and smoke can all indicate that there is an issue with the car that needs to be addressed. Smoke is a tricky one because some car smoke is normal, but it could also indicate a serious problem that needs to be fixed as soon as possible.
So, what does car exhaust smoke say about the health of your engine and vehicle? National Tyres and Autocare produced this infographic to provide some insight.
No Cause for Concern
Smoke coming from the exhaust that is thin and white is to be expected and not a cause for concern. This is simply a result of the internal combustion engine warming up and creating water vapour (not actually smoke).
Cause for Concern
Thin white smoke is normal, but if this is thicker and more continuous then this could be a cause for concern. Thick white smoke often is a result of coolant leaking into the exhaust, which indicates a failed head gasket. Alternatively, it could be a cracked cylinder or engine block, so you need to get the engine looked at as soon as possible to identify the cause.
Blue smoke can be alarming, especially when it is usually accompanied by a burning smell. This indicates that engine oil is burning, which could be due to cylinder walls that are worn, damaged piston rings or leaking valve seals – this often occurs when a car has covered a lot of miles and will require new seals. Keep in mind that if the engine oil has recently been changed, you might see blue smoke temporarily as excess oil is burned off.
In a petrol car, black smoke indicates that the car is burning too much fuel. Changing the air filter may fix the issue, but if not you may need a professional to check the fuel injectors and the fuel pressure regulator. In a diesel, black smoke could be a build-up of soot from unburnt diesel which can build up over time. Driving faster may dislodge the soot, but if not then you may need to get a professional to take a look.
Getting Your Car Checked
It is recommended that you get your car seen by a professional as soon as possible if you notice a continuous stream of coloured smoke, which could indicate a serious issue that makes your car unsafe to drive.
Hopefully, this information will help motorists to better understand any smoke that is being emitted from their car and help them to get the issue resolved as quickly as possible.