Back to all

No Yolk! Rotten Egg Smell (Sulfur Smell Causes)

December 4, 2022

The pungent smell of rotten eggs can send people running for the hills.  So when that odor is inside your vehicle, yikes!  Yolks!  The good news is that a trained service technician can search the source of that smell and stanch the stench… that comes from another words that begins with S.  Sulfur.

Fuel contains small amounts of hydrogen sulfide, but they're enough to stink up a vehicle when it's not properly burned.  You may know that the smell of rotten eggs can often be a sign of a catalytic converter that isn't working the way it should.  That could be due to age, damage or an abundance of oil that's clogging it up. 

If a sensor in charge of managing the fuel has failed, the engine can run with too rich of a fuel mixture.  That can overload the catalytic converter and allow some of the byproducts to escape without interruption from the chemical reaction that is supposed to prevent them from going out the tailpipe.

There's another possibility, but it's usually only in stick shift vehicles.  That's leaking, old transmission fluid.

Catalytic converter repairs are best left to a professional. Technicians at your vehicle service facility have equipment and training that can help them pinpoint the cause of this funky fragrance.  Once the cause is found, repairs made and/or parts replaced, the smell should go away fairly rapidly.

Tuffy Joliet (South Plainfield)
2031 SR 59
Joliet, Illinois 60586
815-436-1829

More articles from Tuffy Joliet

Your Vehicle's Other Power Plant (Alternator Replacement)

July 6, 2025

Your vehicle's engine is probably the first thing that comes to mind when you think of a power plant. But it has another power source that is vital as well: the alternator. The alternator is what puts out the electricity that powers such things as your lights, power windows, sound system, and na... More

In That Case? (Transfer Case Exchange)

June 29, 2025

Ever wonder how all-wheel-drive or 4-wheel-drive vehicles get the power from the engine to the front and rear wheels? The magic happens in what's called a transfer case. In some all-wheel-drive vehicles, it's sometime called a power take-off unit, or PTU. Inside the transfer case is a set of gea... More

Steer Me Right! (Failing Power Steering Hose)

June 22, 2025

Most drivers love how easy it is to turn their vehicles, and they have power steering to thank. Engineers have figured out a way to take some of your engine's power to help you turn. Without it, steering can be quite a chore. New power systems are electric, but there are still plenty of the old... More