Why is there smoke coming out of my exhaust?

What does it mean, and should I be worried?  

A bit of white smoke from your car exhaust on a cold morning may just mean steam which is nothing to worry about.  

What, then, is an abnormal amount of smoke and when should you be worried? 

Cars shouldn’t be blowing lots of smoke from the exhaust (especially newer models fitted with all sorts of filters in the engine to prevent pollution) and if you’ve been properly servicing your vehicle regularly this issue should have already been addressed or prevented.  

There are three colours of smoke that could indicate a problem with your engine, any of which you should take note of if your car is produces an excess of.   

White Smoke 

White smoke coming from your exhaust could mean many things, but this is typically a problem related to an engine running too hot. Your mechanic may first inspect your cooling system components because if this is the cause of the problem and it is left untreated, your engine maybe run into much more serious problems.  

Remember: A little bit of white smoke when you start the car could just be the engine warming up and getting rid of condensation but a lot of smoke when the car is running may be a sign that something is wrong under the hood. As soon as you notice any signs, it’s best to book in your vehicle for a service appointment ASAP.   

Blue Smoke 

Blue smoke typically points to an issue with oil. Although it is called “Blue Smoke”, this can also be perceived as purple, grey, or very light blue smoke. Aside from the smoke itself, you may also notice a loss of power or the car struggling to accelerate.  

If you have a turbo charged car putting out blue smoke, these indicators may be more likely to occur to your car as blue smoke often means there’s an issue with the turbo charger.  

With regular petrol fuelled vehicles, blue smoke most likely points to burning oil – however this isn’t always the reason.  This can lead to oil going to places under the hood that it shouldn’t go which could potentially catch fire.  

In any instance, if you’ve got blue smoke coming from your exhaust, the best course of action is to pull over and call for roadside assistance. Continuing to drive can be dangerous for you, your car and other road users.  

Black Smoke 

Black smoke from the exhaust indicates an issue with the fuel. This would mean that the fuel is contaminated or mixing too much with the engine oil.   

If you only ever notice a small burst of black smoke, there most likely isn’t a serious problem but it is still worth mentioning to your mechanic. However, if you’re experiencing a large amount of black smoke rushing out of your exhaust, then this issue should be taken very seriously.  

Your sensors or injection/fuel system may not be working properly, which any of these need to be addressed by your mechanic ASAP. Ignoring or putting this off for too long could potentially result in your car no longer being road worthy and marked as a hazard to other drivers.  

How to Fix 

Diagnosing or isolating the problem is essential. The sooner you speak with your service department and the more information you can give them, the better. Start by taking notes of what colour the smoke is, how much is bursting out of the exhaust, any loss of power, unusual sounds or change in performance.  

To avoid any further damage to your vehicle, it is best to have it towed to a service centre.  

Our team at Bigboxcars Service & Tyres are equipped and capable to diagnose a smoky exhaust, address the issue and have it fixed so you can get your vehicle back on the road safely again.  Of course, regular servicing helps to stay on top of any issues that arise and can even prevent them from happening in the first place.  

If it’s been a while since your car’s last service, get in contact with our team and make an appointment.