There is never a good reason for your vehicle to smell like gas. Whether you are sitting inside it, or standing near it, if your BMW smells like gas, then you most likely have a problem. Is it a big problem, like a fuel leak? Or is it a little problem, like a leaking oil cap? Either way, smelling gas and leaking fuel can be dangerous. Let’s look at some examples to help you narrow down the reason.
6 Common Causes
These are a few of the more common causes why your BMW smells like gas. It is important to fix any of these issues as soon as possible. Leaking fuel and fumes can be dangerous and lead to expensive repairs if left unaddressed. Smelling those toxic fumes may also trigger headaches, nausea and even cause lasting damage to your brain. Be safe and get your BMW diagnosed by a qualified technician.
Leaking Oil Cap
The oil cap has a very important gasket or O-Ring under the cap. When this gasket gets worn or damaged, oil and fumes leak into the engine compartment. The plastic cap can also degrade and crack over time, allowing fumes to escape. These fumes are then sucked into the HVAC fresh air intake, and right into the interior of the car. Replacing the gasket or cap is usually a simple and inexpensive fix you can do yourself.
Injector or Fuel Leak
The fuel injector in your BMW has rubber O-rings or seals that can dry out and crack. When they get cracked, they allow fuel to leak out. This leak can be seen and smelled around the injector, under your hood.
If you have a fuel line leak, there will most likely be a strong smell of gas, and obvious signs of dripping fuel. Since the fuel line is often made of rubber, and unprotected from road debris, it is a common source of leaking.
Loose or Damaged Spark Plugs
Spark plugs have sealing washers that prevent fumes from escaping the combustion chamber. If those washers get damaged, or if the spark plug is not torqued down properly, fumes could be leaking into the fresh air intake and causing your BMW to smell like gas.
Fuel Tank Leak
Your fuel tank may be made of plastic or metal. Its main function is to securely hold the fuel that powers your combustion engine. If your fuel tank becomes compromised, you will likely see wet spots under your car that smell like gas.
- Corrosion: There are several reasons that a gas tank may corrode. Road salt is a common reason, and why you should wash your undercarriage often if you drive in areas that use road salt during the winter. Excessive moisture on the top of your gas tank can, over time, cause it to corrode. Vapors can leak out of the smallest crack and be sucked into the fresh air intake, causing your interior to smell like gas.
- Puncture: While less common, fuel tanks can be punctured. Sometimes a hole may be repaired, or the tank may need to be replaced. Get a qualified technician to inspect and advise the best course of action.
The canister is part of the emission control system and is filled with charcoal. It filters excessive fuel vapors, before going out the exhaust. If the canister is cracked or damaged, it is a good bet that it triggered a Check Engine Light on your dash. It is always a good idea to get the diagnostic trouble code checked when your dash lights up.
Oftentimes, an exhaust leak will have a few ‘tells’. Do you notice a louder than usual exhaust sound, especially when you accelerate? How about a light tapping or ticking sound? If the smell of gas is strong, the leak may be before the catalytic converter. If you suspect an exhaust leak, have a certified mechanic take a look.
BMW Recall: Fuel Leak
According to the National Highway Traffic Safety Administration (NHTSA), BMW has recalled over 130,000 in the USA for fuel leaks and engine stalling (due to fuel leaks). Certain 2007–2012 BMW models have fuel pumps with faulty wiring that can make your BMW smell like gas. If you suspect that your BMW is part of this recall, schedule a service call with a qualified technician to diagnose and repair your vehicle.
We believe in providing BMW owners with a premier dealership alternative. Our technicians routinely take training courses, and our shop uses the latest tools that are specifically designed to diagnose BMW vehicles. If you have any concerns about your vehicle, or you need to take care of an overdue service item, be sure to give us a call. We will be happy to answer any of your questions and schedule a service.
Visit our web site or give us a call at (909) 316-6166 to schedule your BMW service appointment.