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How Your Car’s Exhaust Smoke Signals Different Mechanical Failures

Monday, June 17, 2019

It’s never a good sign if you see smoke coming out from your car’s exhaust, as it could mean any number of things. The exhaust smoke from both petrol and diesel vehicles should be colourless. If you notice a sudden change in the colour of your car’s gas-pipe emissions, don’t ignore it and visit the expert mechanic in south auckland. Different smoke colours indicate problems, including engine problems and mechanical failure. To help you identify such issues, below is a guide to the different exhaust smoke colours, and the problems that each could signal:

Black Smoke

Black or very dark grey smoke points to a fuel related issue. Either one or more cylinders are being flooded with gasoline, flooding the engine with fuel. It could also mean that fuel in the combustion chamber is not burning properly. Alternatively, it could be a sign of an obstruction in the return fuel line, or damaged fuel injectors, sensors or air filters. For older carburettor-equipped vehicles, it could just mean that the carburettor has not been set correctly and that the air-fuel mixture needs to be re-adjusted.

Grey Smoke

Grey smoke generally signals a transmission related issue. It often indicates that transmission fluid is burning, or that there’s a problem with the transmission vacuum modulator. It could also be caused by a faulty turbocharger in the vehicle.

Blue Smoke

Blue smoke indicates that a vehicle’s lubricating engine oil is burning inside the combustion chamber. This occurs with both petrol and diesel-based vehicles. For diesel cars, blue smoke may also mean that too much oil is going into the crankcase and white-blue smoke points to partial fuel combustion or a problem with the injection system. If you only notice blue smoke when starting up a cold engine (and you drive a vehicle with high mileage) the smoke could be caused by worn valve guides or stem seals.

White Smoke

While white smoke may seem like a less concerning occurrence, it’s the most serious of them all and signals a critical engine problem. White smoke is usually the result of coolant being burnt along with the air and fuel mixture in the combustion chamber. This generally happens when there’s a cracked cylinder head, cracked engine block or the head gasket is blown.

If you notice smoke being emitted from your vehicle, get in touch with your local mechanic as soon as possible. For a qualified and reputable mechanic in South Auckland, contact Drury Tires.