Why Does My Car Heater Smell Like Rotten Eggs? 6 Surprising Reasons!

Why does my car heater smell like rotten eggs? It’s because of the fuel system, transmission fluid is left for quite a long time without the owner changing it, battery leakage, and catalytic converter clogging.

When any of these causes are known, it means to say something has to be done to fix it immediately. For one, the smell of sulfur can damage your health and bring harm when the issue is left unchecked. Please take a closer look at the sections of the car heater for it to operate correctly. There’s actually so much more that you should learn. Without further ado, let’s have a deep look at it!

Why does my car heater smell like rotten eggs


Reasons Why The Car Heater Smells Like Rotten Eggs

Here are the reasons why your car heater smells the same as rotten eggs.


#1. Transmission fluid left for quite a long time without changing it

A smell like a rotten egg can occur with a transmission fluid left for quite a long time. If this happens, it is because the fluid burns and leaks after it gets in contact with hot engine sections.


#2. Car battery leakage

The lead-acid vehicle battery consists of sulfuric acid, the same as a rotten egg and smelly gas. So, ensure to check if the battery does not leak to avoid further damage to your health and other devices. Battery leakage occurs with mechanical defects, especially when frozen, overcharged, or facing electrical issues. You can store batteries in the cabin, truck, or under the seat. The batteries are vented or sealed so that if yours is not filled, it can begin to leak harmful gasses in the passenger compartment. So, fix the battery system immediately. You may also be interested to know about car battery leaking advice and tips.


#3. Clogged catalytic converter

The catalytic converter is a car heater section that turns stinky gasses into non-stinky gasses that you should check out. It does not do its job correctly if it is damaged or worn. The clogging causes more combustion issues. The incomplete combustion sends the fuel not burnt inside the catalytic converter. It should not be there as it only clogs the honeycomb pattern with the catalyst no longer doing its job. The clogged converter can bring hazards requiring addressing immediately.


#4. Dirty vents

The manufacturer advises any user to take the vehicle in for a regular inspection and service through the manual. The car’s vents can get dirty like the house’s vents. The entire system can become contaminated, resulting in a burnt smell because the debris, dirt, and dust are burnt out. Many things can get trapped in the vehicle’s ventilation system, like the leaves and pine needles. The burnt smell can come from the heater blowing the air out to those things.


#5. Engine debris

Something can get stuck in the engine, causing a bad smell. The leaves and pine needles can get caught in the machine. That is true with debris on the road pulled in front of the grille. There are many things to find in the engines like insects and plastic bags. Pulling it over is likewise recommended if any rotten smell occurs after turning the heater. The next is to turn on the hazard lights for safety and open the hood to check it. Maybe, your road has picked up something like a shopping bag so remove them.


#6. Heater core

The heater core may be running out of a mist which is one answer why does my car heater smell like rotten eggs. Other signs that indicate a decline in a heater core include window fogging and car overheating. Moreover, the comfort system services the vehicle’s heater core, so ensure you stick with the service schedule. Replace the heater core and prepare to pay a cost of 600 to 900 dollars. Thus, the regular servicing is going to be worth it.


Reasons For Fixing It Immediately

Fixing this issue is on top of your to-do lists. For one, it can mean danger to contact or breathe hydrogen sulfide. It causes skin irritation and depresses both the respiratory and central nervous systems. In addition, it causes coma, dizziness, difficulty in breathing, and many more symptoms. There is not a prolonged exposure or known antidote leading to death. The sulfuric acid inside the car battery causes thermal and chemical burns, and difficulty breathing. The leaking battery can quickly damage the engine sections with acid eating through the plastic and metal. Moreover, the catalytic converter gets excessive fuel not burnt and turns out overheated with fuel ignition in the car itself. Thus, this can result in a vehicle fire.


It’s A Wrap!

Now you learn the answer to the question, why does my car heater smell like rotten eggs? You surely would not want this smell to stay lingering on your car. So, the best way is to resolve the issue right away and to get things back to normal. It could be associated with engine debris, heater core issues, dirty vents, clogged catalytic converter, etc. Once you know these reasons, have it fixed immediately to get it back in working condition. Do some quick fixes so that it serves its purpose again with using the car while driving with your family. It’s best to also know why car heater not working and why does my car heater blow cold air.

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