Drivers issued warning over colour of smoke coming from car exhaust

Get the latest Daily Record breaking news on WhatsApp

Our community members are treated to special offers, promotions and adverts from us and our partners. You can check out at any time. More info

Join us on WhatsApp

A roadside expert from the AA has shared advice on what to do if you notice different coloured smoke coming from your car's exhaust. While white smoke on a cold morning might be due to condensation, a smoking exhaust often indicates a problem.

Blue smoke typically suggests your car is burning oil, grey smoke may indicate oil burning, a faulty turbocharger, or fuel system issues, and black smoke signals excessive fuel consumption. If left unchecked, these issues can lead to car complications or, in extreme cases, pose significant dangers.

Shaun Jones, an AA patrol expert, has offered guidance on what to do if you spot white or blue smoke coming from your car's exhaust. White smoke isn't always a cause for concern, but drivers should remain vigilant.

Shaun advises: "If you notice white smoke coming from your car's exhaust, it's best not to continue driving. While short drives may be safe if the smoke is due to condensation, other causes like a blown head gasket or coolant leaks can worsen with driving."

A blown head gasket is a common culprit, causing coolant to leak into the combustion chamber, where it burns with the air-fuel mixture, producing smoke. This requires immediate attention to prevent further engine damage, reports Coventry Live.

Shaun explained: "If there's a coolant leak, it's important to locate and repair the source, whether it's the radiator, water pump, or worn seals."

A leaking radiator can cause head gasket failure, with coolant leaking and burning alongside the fuel. If white smoke emerges because coolant has leaked into the combustion chamber through a crack in the engine block, mixing with the air-fuel blend and burning off, be alert for warning signs such as engine overheating, loss of coolant, oil contamination, and reduced performance.

Should the cylinder head crack, coolant will mix with the air-fuel mix, burning off and resulting in white exhaust smoke. Shaun noted: "A cracked engine block or cylinder head may need specialist welding or parts replacement."

The presence of foam in engine oil is an indicator of coolant contamination, typically from a blown gasket or cracked block, which leads to coolant burn. Overheating in the engine can generate white smoke and further damage the engine block or cylinder head, leading to cracks and leaks that exacerbate the situation.

Significant drops in the coolant level may signal a leak or a defective component, such as the water pump or radiator. It's vital to properly fill and seal the coolant system to prevent these issues and maintain optimal engine temperature, avoiding any potential problems with air getting into the cooling system.

Air caught in a car's cooling system can wreak havoc, interrupting the coolant flow and potentially causing the engine to overheat. If the coolant is unable to move as needed, it could lead to localised hot spots within the engine and drive coolant into areas it shouldn't be, such as the combustion chamber.

Shaun commented: "If air is trapped in the cooling system, the system is likely to need bleeding." This procedure should only be done by a qualified professional.

Blue smoke emanating from car exhausts is typically indicative that your automobile is burning oil. Shaun cautioned: "For blue smoke, it's important to act quickly. Avoid driving, as continuing to drive can exacerbate the problem, leading to more damage and costly repairs. You may also experience reduced fuel efficiency and engine performance issues. Blue smoke will cause your car to fail an MOT test and might violate emissions laws. It's best to get your car checked by a mechanic as soon as you notice the smoke to prevent further damage. If concerned, consider breakdown cover for professional assistance and car maintenance advice."

Story SavedYou can find this story in  My Bookmarks.Or by navigating to the user icon in the top right.