You can tell how healthy a car is from its waste, i.e., exhaust smoke. Although some types of smoke are nothing to worry about, others indicate car problems that should be dealt with right away. Use this color-coded method to diagnose possible causes and find out how to resolve them.
Clear Exhaust Smoke
If the gas coming out of your car’s exhaust has no color, then you are in the clear. You can expect to see some condensation, such as water dripping from the tip of the tailpipe. If it is only a little water, it is normal. However, if the amount of water increases to a point where you notice it and are concerned, see a mechanic.
White Exhaust Smoke
As soon as exhaust smoke starts taking on a color, pay careful attention. White smoke that appears when you start the car and disappears when the engine is warm is not a concern. If you usually use the car for short trips, drive a little further on some days to keep condensation from corroding the steel in your tailpipe.
White exhaust smoke might be a problem if there is a significant quantity and it appears thicker. It might be that the coolant is leaking. Leaking coolant can form bright-colored puddles of fluid under your car and can cause AC problems as well as engine overheating.
Thick, white smoke from the exhaust can also mean the head gasket is faulty. Whether it is caused by leaking coolant or gasket failure, you need to go into the auto repair shop to have it inspected.
Grey Exhaust Smoke
If you notice grey smoke from the exhaust, drive into a garage and check your oil levels. Too much oil can cause this. It is also quite common for vehicles with turbochargers that need to be replaced to produce grey smoke.
Another potential cause is leaking transmission oil. If this is the case, you might also spot a thick red or brown fluid leaking under the car and/or experience problems with your clutch and gearbox. You should see a professional urgently in this instance.
If none of the above apply, a possible cause could be a faulty PVC valve. When unburnt fuel sits or sinks to the bottom or lower part of your engine, the PVC is the one that pulls it to the top. Grey smoke caused by PVC failure can be a tad dramatic and worrying but repairs are usually simple.
Blue Exhaust Smoke
One of the best steps you can take when you see blue exhaust smoke is to have your oil checked. Excess oil can seep into the fuel system, and when it does, it needs to burn itself off. This produces a strange burning smell and blue smoke, and sometimes leaves traces of oil on the tailpipe.
Worn piston rings and valve seals can also allow excess oil into the fuel system. It is a common problem with used cars and those with high mileage. These parts need to be replaced by an auto repair specialist. Drivers of turbocharged vehicles might also be due for a replacement if a turbocharger is old and faulty.
Black Exhaust Smoke
If your car is petrol-powered, black smoke could mean it is burning too much fuel. If you know how to replace the air filter, please do so. If not, ask for help from a pro. If replacing air filters does not resolve the issue, your mechanic might have to check and clean the pressure and fuel regulators.
Black exhaust smoke is usually a less serious problem in diesel-powered cars. The common cause is soot deposits that can be dislodged if you drive your car faster. If the smoke does not disappear after this, ask a professional to check if the DPF or diesel particulate filter is still attached to the car.
Diesel-powered vehicles have a warning light that flashes when there is soot buildup. If the light comes on regularly, you may be driving too slowly too often. If your driving style is not compatible with diesel models, it may be wise to switch to a petrol-powered engine instead.
Exhaust smoke can be useful in diagnosing problems with your car. The color of the smoke usually points to the cause and gives you ample time to have the issue repaired before causing further damage. Speak to auto repair specialists about any other symptoms – such as leaks, smells, and car noises – for the best solutions.