The most likely cause of a rotten egg smell in your car is a broken catalytic converter.
The eggy smell originates from the tiny amount of sulphur which is within your car’s fuel; if the exhaust system is working effectively this smell is not given out as the catalytic converter transforms it into the odourless sulphur dioxide.
However, if the converter breaks or the filters within it wear down, this conversion process cannot take place. Therefore, the smelly egg odour is released. Thus, the smell is the result of an issue with your emissions system.
The solution? It is likely a new catalytic converter which is an expensive job. Sorry! Make sure to have a mechanic inspect your exhaust system to pinpoint the exact issue and carry out the respective repairs.
Other Reasons for Rotten Egg Smell in Car
There are other potential (and less expensive) explanations for the eggy smell, although they are less common causes. Firstly, it could simply be old transmission fluid. If you aren’t changing/replenishing the fluid as much as your maintenance schedule instructs. It is possible for the old fluid to leak into other systems and give off that egg odour.
Secondly, it may just be that your engine is overheating. Although that would normally result in a burning smell, it is not unheard of for it to smell a little eggy!
Ensure that any untoward smells/problems are dealt with efficiently to prevent any further damage to your car’s components and increasingly expensive repairs.
Noticed any other weird noises or smells coming from your car? Use our other diagnose it blogs to uncover the issue now!