Why does exhaust smell like gas

However, some cars seem to have really smelly exhaust fumes due to a number of different reasons depending on the smell in question. You may also notice that it creates smoke from the tailpipe bluish in color. Ever been riding along and suddenly smell rotten eggs? Sulfur is found in gasoline, and is turned into hydrogen sulfide in the combustion process.

However, the catalytic converter changes it into sulfur dioxide. This has no odor at all. As the cat fails, it stops changing hydrogen sulfide into its odorless counterpart and the result is a strong smell of rotten eggs from the exhaust. There are many ways this can happen. A pinhole leak in a coolant hose can spray antifreeze onto a hot engine component, which boils the coolant away and creates that smell.

It can also contaminate oil and be burned in the engine that way. Diesel exhaust smells much stronger than the exhaust from a gasoline engine. If you notice any of these smells coming from your exhaust, you should have the problem diagnosed as soon as possible.

You might not care about how your car works, but this quick explanation will help you to understand where your problem is. Any step of this fuel-exploding process can have a problem.

Finding the problem area takes a little bit of troubleshooting. If you want to find the problem yourself, it will help save some time and money at the car shop. It might even save a trip altogether if the solution is easy enough. This may be coming from the engine itself, the fuel line or the exhaust system where gas emissions evaporate.

Simply breathing in gas fumes can make you sick, and in extreme cases, it can kill you. If your spark plugs were never tightened to the right torque, they could have loosened over time. In this case, the fumes will come out of your combustion chamber and go right into the air intake for the HVAC system of your car.

In other words, the engine will spew gas fumes right into your air vents. Your spark plugs will have washers on the threaded part that seal everything. If these washers are cracked, missing, or broken, then the gas smell could be coming from these guys. Check the spark plugs and see if they look okay. If they do, carefully remove each one and remember where they go.

Mixing them up when you re-install them will cause your car not to start. It might be easier to just remove one at a time and put it back after. Just loosen the spark plugs until you can hand-tighten them.

Screw it in as hard as you can by hand. Grab your wrench and give it a quarter turn. Now you should be at the right torque. At this point, you can repeat this step for all of your spark plugs. This will make sure that all of your plugs are seated at the right torque. This might be one of the more common causes for the gas smell in car.

The oil cap is, no surprise, the cap to your oil reservoir. This is the part that you take off when you change your oil. Pop the hood and locate the oil cap. Look around the cap. Is there a lot of dirt and oil stains below the cap? Take off the cap and look at the O-ring on the underside of it.

Luckily your local auto part store will stock this part for a few dollars. Finally, take a look at the cap itself. If the cap is cracked or busted, then you can just replace the whole piece. If nothing else, check out the salvage yard and see if you can grab an oil cap. Another reason why you may smell gas when you start your car or are driving your car is because you have a failed pressure regulator.

The failed regulator can burn fuel until the mixture is too thick or too thin. Burning excess fuel not only wastes gas, but also causes fumes to sit inside the exhaust, which is what you may be smelling. If you notice a decrease in your fuel efficiency and it seems like your car has weaker power than before in conjunction with the scent of fuel, bad fuel pressure may be the cause of your gas scent. The final reason why you may smell the scent of gas when you start up your car is because you have a gas leak.

You may have a leak in your fuel line or you may have punctured your fuel tank. If you suspect you have a leak, you will notice a puddle of gas under your vehicle. When your fuel pressure regulator goes bad, it will interfere with your fuel mixture and cause it to either be too thin or too rich, and when the fuel mixture is off, it causes your engine to burn gas excessively.

If your engine is burning too much gas, it will increase the amount of gas fumes coming out of your exhaust. In addition to the odor of gasoline, decreased fuel efficiency and engine power are also signs of a bad fuel pressure regulator. If you smell gas in your car, make sure to visit a qualified service professional right away.