There is no doubt about it at all—strange smells coming from your vehicle can be a little unsettling. It happens all the time day, you might get inside your vehicle only to be hit by a super stinky mysterious smell. Many common objects and liquids can cause strong odors and smoke something as simple as coffee, soda or milk spilled on one of your seats.
The problem is that these odors might be caused by a mechanical problem. To treat the issue, it is important to discover the source of the problem and work hard to remove it.
The first thing that all of us at Anderson Behel in Santa Clara, CA would like to tell you is once you start smelling weird odors, ventilate the car’s interior to protect your health. Some smells and smoke will be less worrisome than others, but all can be easily treated once you know why they’re happening.
Maple Syrup: After your motor has warmed up or possibly even after it has been shut down for a few minutes, if you smell maple syrup and it is not your doggie bag from Pizza Hut, coolant is leaking. A strong smell inside the passenger compartment likely means that you have a bad heater core.
Gym Socks: If you turn on your heater or A/C and the car reminds you of your high school gym locker, it is probably mildew growing in you’re A/C evaporator. Try turning off the A/C and turning the fan on high to dry out the evaporator.
Litter Box: If your vehicle begins to smell like your dog’s favorite place to do its business, gear lube is leaking within the system. That is actually sulfur you are smelling. Look for drippy, oily stuff under the automobile, and once you find it, get to your mechanic, and please--don’t put it off.
Rotten Eggs: Similar to the previously stated issue, sulfur causes the smell (no matter what, it is never good). This may be caused by a fuel-injection problem, and can be fixed by a skilled mechanic, but more than likely, it is a failed catalytic converter.
Hot Oil: This means that oil is leaking onto the hot exhaust manifold. Leaky valves do not often leave a drip on the floor, so look for smoke and try to stem the leak.
Burnt Carpets: This means that your brake pads are seriously overheated. If you smell this odor under normal driving conditions, you have got a dragging brake. Always check the temperature of the brakes by hand — the hot one is probably the smelliest.
Sources: AAA and DMV.org