Car Smells Like Rotten Eggs and Mischief
If your car has a foul odor when you start it, it could be the cause of your nausea. If your car smells like sulfur or rotten eggs, something is definitely wrong. Here we look at the possible causes of rotten egg smoke in your car and the best way to get rid of the smell so that it doesn’t linger and you and your passengers can seek fresh air.
Why does my car smell like rotten eggs? If your car starts to smell like rotten eggs, there are a few possible causes. And before you rush to the mechanic to have the problem diagnosed and fixed, you need to know more about what’s going on first.
Whether you want to fix the problem yourself or avoid being taken advantage of by the mechanic, here are 5 reasons why you might have a rotten egg smell in your car.
1) Faulty catalytic converter
This is the most common cause of a rotten egg smell in your car. If all of your vehicle’s catalytic converters are working properly, they convert toxic chemicals into harmless H2O compounds (also known as water or steam).
But over time, these harmful chemicals and gasoline can clog the catalytic converter parts, which means it can no longer convert gases properly. When the catalytic converter is clogged, hydrogen sulfide turns into sulfur dioxide instead of water or water vapor, which causes a rotten egg smell.
2) Faulty fuel pressure sensor
If you notice your car smelling like rotten eggs, it is often because a faulty fuel pressure sensor is pumping too much fuel into the system, causing the catalytic converter to become clogged because it cannot handle that much fuel at once.
This is especially true if it occurs before the catalytic converter is expected to fail, which is after about 10 years or 200,000 miles. Keep in mind that if your fuel pressure sensor is faulty, but you still have a rotten egg smell, you should replace your catalytic converter.
This is not an either/or solution, it’s simply a question of whether you should replace both components to prevent your vehicle’s new catalytic converter from wearing out prematurely.
3) Old Gear Oil
If you drive an older vehicle, especially one with a manual transmission, you probably need to change your transmission fluid from time to time. The exact maintenance intervals are specified in your owner’s manual, but if you don’t change it on time, the seals can wear out and leak where they shouldn’t.
4) Dead Animals
Everything we’ve covered so far has been mechanical issues, but there are a few other possible explanations: A more common problem than you might think is a dead animal (usually a mouse or rat) in the engine compartment, exhaust system, HVAC system, or inside your car.
When it gets cold, animals look for a warm place to sleep, and often the engine compartment or exhaust system provides that. The problem is that they may die when you start the car, and then their body may start to decompose.
As you might imagine, this is not a good smell, and can cause your car to smell unpleasant.
5) Forgotten/Hidden Food
The rotten egg smell may just be rotten eggs. While this isn’t the most likely scenario, sometimes food can slip around in your car and end up under the seat. Or maybe you were going through a bad breakup and your ex-lover cracked an egg in a hidden part of your car.
Either way, if you smell rotten eggs every now and then in your car, it’s because there’s rotten eggs, rotten milk, broccoli, or other rotten food in there.
Is it okay to keep driving my car? You might think that since you probably smell rotten eggs from your exhaust system, it’s safe to drive for a while. This is true for most cars, but we strongly recommend that you don’t do it because of the potential drawbacks. A clogged catalytic converter can overheat and catch fire, which is of course the worst case scenario, but that doesn’t mean you should ignore the rotten egg smell in your car.
