What Can Cause Your Car to Smell Like Rotten Eggs?

We spend so much time in our vehicles that they sometimes feel like home. So when something is off, like a strange noise coming from the engine compartment, we know immediately. The same is true for odors inside the vehicle. For example, the rotten egg smell. You've looked everywhere inside your vehicle, but the source of the smell isn't in the vehicle.

The rotten egg smell comes from a small amount of hydrogen sulfide (sulfur) that didn't combust with the rest of the gas inside the engine. It should have been converted into odorless sulfur dioxide. The obnoxious smell won't hurt you, but it signifies something is wrong.

  • Damaged or blocked catalytic converter: When gas combustion happens, the exhaust contains other gasses like hydrogen sulfide. The catalytic converter turns the hydrogen sulfide into sulfur dioxide, which then comes out with the rest of the car's exhaust. The intent is to reduce ozone-harming gas that contributes to climate change. If your car's catalytic converter doesn't work, it must be replaced.
  • Old transmission fluid: If you own a car, you should maintain regular maintenance, like changing the oil and the transmission fluid. In addition to not working properly, old transmission fluid can leak into the engine producing a rotten egg smell. If this is the source, flushing out and replacing the old fluid should stop the smell.
  • Faulty or failing fuel system pressure sensors: Cars have dozens of sensors including the fuel pressure sensor which regulates how much gas the vehicle uses. If this filter is clogged or damaged, the wrong amount goes into the engine for combustion. Too much fuel from the combustion chambers can smell like rotten eggs because the sulfur hasn't been through the catalytic converter. Replacing the sensor fixes that problem.

Rotten Egg Smell Means Something Else Could Be Wrong

Once the problem gets fixed the smell will quickly stop. The important thing to remember is that smell could signify a much bigger problem like an overheating engine. Knowing and understanding the odors that can harm your vehicle is a good idea.

If you need catalytic converter repair, call or stop by Auto Centric today!

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