Motorists across Britain are being urged not to ignore a rotten egg or sulphur-like smell coming from their vehicle, as it could signal a potentially fatal carbon monoxide leak. Kazimieras Urbonas, Supplier Excellence Manager at Ovoko, an online marketplace for second-hand car parts, warns that while many drivers focus on dashboard warning lights, unusual odours are often overlooked.
"It's common for drivers to just dismiss odd smells as minor annoyances, but certain odours are your car's way of screaming for help," said Urbonas. "What starts as an unpleasant smell could quickly become a life-threatening situation if left unchecked." The distinctive rotten egg odour typically indicates a faulty catalytic converter or fuel system issue, allowing hydrogen sulphide gas to escape.
Even more concerning is the detection of exhaust fumes inside the passenger compartment, which could allow carbon monoxide—a colourless, odourless, and lethal gas—to accumulate. Symptoms of carbon monoxide poisoning include headaches, dizziness, nausea, confusion, and extreme fatigue, and can escalate to loss of consciousness or death, especially in enclosed spaces with windows closed and heating on.
Urbonas advises drivers who notice a suspicious smell to pull over safely immediately, open all windows, and turn off the engine. "Don't try to tough it out or convince yourself it's nothing," he said. Occupants should exit the vehicle and seek fresh air. If anyone displays serious symptoms such as disorientation, breathing difficulties, or loss of consciousness, dial 999 without delay.
Drivers should not restart the engine or attempt to drive to a garage. Instead, the vehicle should be towed to a qualified mechanic for a thorough inspection of the exhaust system and catalytic converter. The risk is heightened in winter when windows are closed and heaters are running, and in traffic congestion where exhaust emissions from other vehicles can worsen the problem.
