What Does It Mean If My Car Smells When I Turn It On?

Sun Auto Service Expert, published on 07/25/2016

We all love that new-car-smell and want it to remain for as long as we own our cars, but eventually it fades and another smell can fill the void. Unfortunately, sometimes that smell is unpleasant and can indicate a number of issues going on under the hood. Sun Auto Service wants to inform Texas and Nevada motorists of the common potential vehicle issues behind those mysterious odors.

Smell: Sweet

Catching a whiff of something sweet after either warming up your engine or turning it off could be a sign that you have an engine coolant leak. There are several places where coolant commonly leaks, including:

  • Heater hose
  • Radiator
  • Radiator Hoses
  • Thermostat
  • Water Pump
  • Intake manifold gasket
  • Heater core

No matter the source of the sweet smell, it’s best to have it addressed as soon as possible.

Smell: Sulfur

A sulfurous smell, often compared to the smell of rotten eggs, can relate to your vehicle’s battery or catalytic converter. If a battery is frozen, overcharged, or has otherwise shorted out internally, it may cause the case to vent gas. It is important to have your vehicle inspected as soon as possible, as the sulfuric acid in batteries can cause corrosion or eat away at other vital engine parts. However, the stench can also be caused by a failing catalytic converter. Hydrogen sulfide, found in the exhaust, is produced by a touch of sulfur in fuel. Once it enters the catalytic converter, it should convert to sulfur dioxide. If you smell rotten eggs, it’s likely not doing its job and calls for an inspection by a professional.

Smell: Musty/Mildew

If you haven’t been to the gym recently, but still smell what can only be described as a “locker room” coming from your vents after turning on your air conditioner or heater fan, there’s a good chance you have mildew growing from the moisture in your air conditioner evaporator. You can try to take care of the issue by running the fan on high to dry the system out, or you can spray an antibacterial spray, such as Lysol, into the dash vents. We recommend taking your vehicle by one of our Texas or Nevada service centers if neither of these solutions works.

Smell: Gasoline

The aroma of gasoline could be an indication that you have a fuel leak if you catch the scent whenever you turn on your heater or vent. Tip: Avoid “topping off” your fuel tank when pumping gas. After the pump clicks off, do not continue adding fuel. Overfilling the system can damage the evaporative system that vents fuel tank pressure. Just like with engine coolant, gasoline is highly toxic, and it’s a potential issue that should be addressed by a professional auto repair technician, sooner rather than later.

Schedule an Appointment Today

No matter how normal or out-of-the-ordinary a smell is when you’re behind the wheel, don’t hesitate to get in touch with us here at Sun Auto Service. We have locations throughout Nevada and Texas.