why does my car smell like rotten eggs? — What Should You Do?

There are many times we find ourselves asking why does my car smell like rotten eggs. In this case, the rotten egg smell mostly indicates that there is something wrong with some engine parts.

Most probably, the faulty engine parts are leaking Sulfur and other gases that are causing your car to smell like rotten eggs.

Cars may have different odors like a new car smells a bit leathery, musty, gas burning, exhaust fume, and sulfur smell. Thereby, each kind of smell is produced due to different causes.

And for that reason, you need to learn how to differentiate the odors and verify the causes. Lastly, you better fix the cause of the smell if it’s dangerous.

Thus, follow ahead to acknowledge yourself thoroughly about the Car smells.

Finding Out the Smelly Red Flags on Cars & What to Do?

It’s not really an exaggeration to think something is faulty in the Car parts after sniffing out some odors. Well, it’s a different story if you forgot to clean up thefood waste from the seats.

Of course, you shouldn’t look away if the situation is more like Why my car smells like rotten eggs, sulfur or burning gas?!

So, let’s learn how should you identify which car smells are harmless, and which are not. Afterward, learn what you must do immediately.

1. Gas Smell in Car

You may sniff of Gas, or petroleum-like smell in your car, even after a while till you filled up the fuel tank.

Most probably it is e to the gas rubbing off to you somehow while you were filling the tank. So, as you got inside the car right after, the odor stayed with you for a while.

However, if the Gas fumes linger for a long while, then it’s worrisome. A long-lasting Gas smell means there can be a leakage in the fuel injector or tank, and the fumes are leaking out continuously.

What to Do?

The problem of leaky gas will harm your engine’s fuel efficiency. As well, the Gas leakage may ignite to fire incident while it comes in contact with engine sparks.

So, to fix that, stop driving to wherever you are and head to the nearest Automobile Repair shop. Then get the top-notch automotive technicians to find the root cause and repair it.

2. Moldy or Musty Odor from Car AC

After long usage of Car AC, the air from AC vents may start to smell sour, moldy like vinegar, or like wet socks.

Well, this can only mean that Air cooler vents and filters have amassed an excess amount of moisture over a period of time.

Therefore, inhaling the musty air coming from the contaminated air filter will get you to catch diseases, and breathing problems.

What to Do?

In case your Car Air cooler gives off sour vinegar, musty, or moldy wet sock fumes, you need to service the AC.

Take your car to the AC Service. Get your Car’s AC vents, filters, and drainers to get squeaky cleaned, and serviced.

3. Exhaust Fumes Inside Car

Exhaust smell is extremely harmful and dangerous, and you should never ever ignore it. Exhaust fumes come from the faulty or leaky exhaust system of the car.

Therefore, the leaking exhaust secretes mostly carbon monoxide fumes which is very hazardous and deadly. It can injure your eyes, and respiratory function of lungs right away in direct contact.

Even more so, itcan kill the person exposed to it in confined places (inside a car) for a significant amount of time.

N.B.:It literally smells like rotten eggs (hydrogen sulfide), sulfuric, or sewer gas.

What to Do?

Exhaust fumes leak when there are some leaky parts in the engine’s exhaust system. Also, if the Catalytic Converter is damaged due to heavy combustion, it can lead to exhaust leakage. As a result, harmful gases leak out of the exhaust chamber while combusting.

The Exhaust System of a car is deep inside the engine, and the design is kind of complex for you to know which part is leaking or damaged. So, you need expert technicians’ help in fixing it as well.

4. Rotten Eggs Odor in Car Interior

The smell of rotten eggs inside the car can mean a lot of issues. It can indicate that you weren’t cleaning your car vents for so long.

Also, it can mean that fuel pressure scales aren’t working, or filter sensors are rusty.  

The rotten smell is not only stinky. Also, it assures that the dangerous gases are leaking through the vents into your cabin. (Like we said in exhaust fumes issue- Hydrogen Sulfide, Sulfurous Acid, and so on). 

What to Do?

Experiencing a rotten egg smell due to fuel system malfunctioning is dangerous. In most cases, it leads to that the whole fuel system and Catalytic Converter are malfunctioning.

Therefore, you must repair your worn-out fuel systems parts like fuel pressure sensors, filters/vents, or catalytic converters.

Moreover, you might also need to change old rusty transmission fluid from the car system ASAP.

5. Burning Smells of Rubber, Fuse, Overheating Compressor

Getting to sniff burning smells inside your car while driving is a bad sign.

If the burning smell is more like burning rubber, then it’s troublesome. Burning rubber smell points to the loosened or worn-out rubber wrench, hose, or belts inside the connection parts under the hood.

On the other hand, if the burning smell indicates the burning of an electrical fuse, or compressor, then those parts are broken.

What to Do?

The burning of Rubber happens when the worn-out rubber connectors rustle around. Then, gets into the contact of hot engine parts, and melts. Even hot fluid leakage can do that.

So, you need proper restoration of those loose rubber bolts/hose, and connectors.

On the other hand, burning of electrical fuse, or compressor, or sensors points out that the particular system is dead, and needs replacements. 

Thus, in both cases proper examination and topnotch repairing or replacement are essential.

1. What should I do if my car smells like rotten eggs or like Sulfur?

Rotten smells point out the faultiness in the old fuel transmission system and the leaky exhaust system. The best way to fix it is to replace the worn-out system and repair any damages causing leakage.

2. How much can it cost to get rid of the rotten smell from the car?

The only way to get rid of rotten egg or hydrogen sulfide smell in the car is to repair or replace the broken parts and systems. Depending on the damages of the parts (faulty fuel pressure regulator), and the shop you’re frequenting, it can cost you approximately $250 to $350.

3. Can I still drive if my car produces burning smells?

No, moreover you should stop driving the car immediately. If you smell like something is burning inside the car like rubber, fuel, or electrical fuse then it means that some engine parts are actually burning. So, don’t drive unless you want to blow up yourself, and the car.

4. How much will it cost to replace a Catalytic Converter?

Well, firstly you need to be sure whether the catalytic converter needs repairing or replacement. It’s never wise to replace Catalytic Converter over a little faultiness. Therefore, it costs a lot to fix Catalytic Converter about $950 to $2500.

Final Thoughts

So, why does my car smell like rotten eggs just means that there are some issues with Car’s engine, fuel, or venting systems. Further, you need to fix those issues as soon as you can to avoid further casualties.

Therefore, you should always be mindful of some weird unpleasant smells inside the car and take necessary measures.

Lastly, be careful while driving, and service/repair sensitive car parts regularly.

Who Worked on This?



I'm the guy responsible for ensuring that every blog post we publish is helpful for our reader.

Mahir Ahmed


I'm the guy responsible for ensuring honest, informative, accurate and helpful guide to the reader.

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