Smell Guide: Engine Edition

If you, like me, have a big family and a lot of sports equipment to tote around, the arrival of spring and inevitable coming of summer mean that whatever gear you’ve been toting around is about to multiply and start to smell. Really, really smell. But there’s a definite art in separating out the smell of whatever’s supposed to be in your vehicle and what might be indicating that you have a problem under the hood. How do you know? Well, first you have to know what the different smells mean. Check it out!

You Smell: Rotten eggs
What It Is: Your catalytic converter is having some issues and is putting hydrogen sulfide into your exhaust. It could either be a fuel injection problem, or your cat is failing. This is, unfortunately, a pretty expensive repair. But if you smell the rotten eggs when your car is not running, you should probably check for something inside the car.

You Smell: Sulfur
What It Is: When you smell sulfur in your car all the time, you can assume that it’s gear lubricant leaking from the manual transmission, transfer case, or differential housing. There are sulfur compounds in the oil that serve as extreme-pressure lubricants for the gears in these parts, and after being in use for a few years this substance can get kind of gross. Look for puddles of oily, viscous stuff under your car. If you see this, you should take your vehicle to our service department.

You Smell: Maple syrup
What It Is: Coolant has ethylene glycol in it, which smells sweet but is definitely toxic. If you’re smelling it, that means there’s a leak somewhere in your system. You should take your vehicle in to get looked at, though this is a pretty easy fix.

You Smell: A gas station
What It Is: Unless you’re at a gas station, you shouldn’t smell this. It’s straight up gasoline, which should be inside your car and not outside of it. If your car is older (i.e. before 1980) then you might smell this when you turn your car off, but if your car is newer than that, the smell of gas means that you’ve got an issue. This could be a leak from a fuel injection line or a fuel tank vent hose in your engine.

You Smell: Hot oil
What It Is: The easiest to diagnose, this is hot oil. But the oil is getting hot because it’s leaking onto the exhaust manifold, which is hot when your engine is running. It’s not a pleasant smell by any stretch of the imagination, so take a look around your engine and keep an eye out for smoke. If you can find the leak, try to stem it, then bring your car into our shop, and fast.