There is a lot of smoke coming out of my exhaust – what do I do?
• Exhausts reduce the amount of toxic chemicals in fumes to improve emissions
• A healthy exhaust system will maintain fuel efficiency and emissions levels
Excessive smoke clouds from your exhaust are never a good sign, so our advice if you encounter this issue is to stop the vehicle and park it in a safe place off the main road. Next, call someone to recover the vehicle, if you are a member of a roadside assistance provider such as the AA, RAC or similar, then call them.
However, please be aware that on start-up some smoke may be released from a vehicle. This is totally normal, and should only be considered a problem if the exhaust continues to smoke during a journey.
Smoke can come in various different colours, including black (usually diesel), grey, white and blue.
Lots of smoke is usually an engine issue, not an exhaust issue, but it will have an adverse effect on your exhaust anyway. CATs and DPFs will be damaged by oil entering the exhaust from the engine, with the internals of the devices severely compromised if the problem is left to continue. As a result, these devices may fail or become blocked, a situation that can only be resolved by replacement.
By continuing to operate the vehicle under such conditions, you also risk failing the MOT test. Your vehicle will be declared unfit for the road until the issue is rectified.
Engine issues are caused by a great many things failing including seals and ancillary equipment, however the most common cause of lots of smoke is the wrong fuel being put into the car petrol/diesel or vice versa. It’s easy done, so don’t be embarrassed, but don’t be tempted to drive to a garage or drive home. Doing so will really damage your car, compromise your safety and potentially end in a larger repair bill.