2012 Mazda MAZDA3 fuel system problems

Filed Sep 26, 2025 · Fuel system · WA

The car leaks gas when the tank is full and if the car is inclined slightly. I've noticed the problem several month ago with an occasional odor but finally saw the gas leaking recently when it was parked on a sloped street.

Filed Apr 2, 2025 · Fuel system · PA

Our fuel tank is leaking for no reason. Brought it in last year (2024) for state inspections and let them know we smell gas when we park sometimes. They poke around and find nothing, but note there is a faint gas smell and to bring it to the dealer. We take it to Mazda to see if they can fix, they find nothing and charge my wife $250. Fast-forward to a year later, go for the same state inspection and we get failed. Our mechanic says theres a noticeable gas leak from the fuel tank and to take it to Mazda. There is clearly some issue with the fuel tank parts. The car itself only has 77k miles and it is 13 years old.

Filed Feb 10, 2025 · Fuel system · 81,000 miles · PA

The contact owns a 2012 Mazda Mazda3. The contact stated that after refueling the vehicle, there was an abnormal gasoline odor inside and outside the vehicle for the next 5 days, prompting the contact to only fuel the vehicle halfway. The contact observed fuel leaking underneath the vehicle near the fuel tank. No warning lights were illuminated. The vehicle was taken to an independent mechanic, who diagnosed a failure with the welded fuel tank nipple fuel line connector. The contact stated that the component was cracked along the bottom of the weld. The contact was informed that the fuel tank needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 81,000.

Filed May 20, 2023 · Fuel system · NC

After topping off my fuel tank at a gas station, fuel begins to leak from the top of the tank. Prior to noticing the leak, I had noticed a strong smell of gas after topping off and driving home. Symptoms include smell of gasoline, and a gasoline puddle on the ground. The fuel appears to be leaking from the top of the fuel tank, running down the side, and dripping onto the ground. Because of other nearby components that generate heat, this is a very dangerous situation that may lead to fires. Other 2012 Mazda 3 owners have experienced the same exact situation. The following threads shows comments from various people that have experienced the issue. The component that seems to have failed is the vent hose which allows gasoline to seep to the exterior of the tank. Fuel leaks are extremely dangerous as sparks, matches, cigarettes, or other heat sources can ignite the fuel leading to a total loss. https://www.mazda3revolution.com/threads/fuel-leaking-from-gas-tank-area-after-filling-up.236569/ https://www.mazdaspeeds.org/index.php?threads/resolved-fuel-leak-by-tank.14228/ Quotes for repair seem to vary with some people claiming up to $900.

Filed Aug 27, 2020 · Engine, Fuel system · ME

When I drive down the road.my car speeds up and I don't press on the excilerator any harder. The cars idol goes up and down when driving and at park. This happens on all types of road ways. Sometimes it speeds up on me so fast I have to hit the brake while driving on the road.

Filed Aug 1, 2020 · Fuel system · 90,000 miles · CA

Smell of fuel is very noticeable after filling up the gas tank. Further investigation indicates there is leaking somewhere near/around the tank but not on top where the fuel pump is. It is observed that the leak happens when tank is filled up full and more so if parked uphill. If filled up full, the leak seems to stop if car is parked downhill. Research indicates several other 2012 mazda 3 owners have experienced the same issue. This is quite dangerous. For a part that is not moving or wearing out, whether the tank or attached hose, to break for a 7-8 year old car is unacceptable. This can cause a fire or explosion leading to death.

Filed Jan 21, 2020 · Fuel system · 78,000 miles · KY

Gas leaking from back of fuel tank after filling it up. It I only fill up half way no leak

Filed Feb 8, 2019 · Engine, Fuel system · 31,740 miles · FL

Tl* the contact owns a 2012 mazda 3. While driving at an unspecified speed, the check engine indicator illuminated. The vehicle was taken to jenkins mazda of ocala (352‑815‑2425, located at 1740 sw college rd, ocala, fl 34471) where the fuel pump and gauge were replaced. The clutch was replaced six moths later. Five months later, the vehicle leaked fluid in the driveway. The vehicle was taken back to the same dealer where the technician diagnosed and replaced the driver's side transmission axle. Seven months later, while driving approximately 5 MPH, the vehicle made a clunking sound and was towed to the same dealer where the technician diagnosed and replaced the entire transmission. The manufacturer was made aware of the failures and offered to provide a discount towards the cost of a new vehicle. The offer was not acceptable. The contact's vehicle was not repaired. The failure mileage was 31,740.

Filed Dec 31, 2018 · Fuel system · 81,800 miles · NC

Fuel filler line leak. When gas tank is full fuel leaks from small whole in line that goes into gas tank. My mechanic says it is where the line is welded to gas tank has broken the mazda service manager tells me it's not an issue that mazda will fix, even though it is a safety issue. My mechanic says that this is an issue with the 2013 models, so if the same thing happens to a 2012 model why it not be repaired by maxda?

Filed Jun 13, 2018 · Fuel system · 98,000 miles · MA

Each time the vehicle is fueled the check engine light come on. I have clicked the fuel cap several times. I have had the cap replaced. There is an evap code showing. The car cannot pass any state inspection