What Happens If a Car Fuel Tank Cap Doesn't Seal Properly?
2 Answers
If a car fuel tank cap doesn't seal properly, it can lead to gasoline evaporation rates being related to the temperature inside the tank. The higher the temperature, the faster the evaporation. However, if the seal is only slightly compromised, the loss won't be significant. You might notice a gasoline smell inside the car, but it's still recommended to replace the cap. There are several scenarios where you might smell gasoline inside the car: 1. The fuel tank cap doesn't seal properly and needs replacement or a 1mm thick layer of grease applied under the rubber gasket; 2. There are fine cracks or damage in the fuel supply line. 3. There is a gap at the connection between the fuel line and the fuel tank (the clamp isn't tight enough). 4. Gasoline smell is emitted outside the car and is noticed when the window is open.
A loose fuel tank cap is something you really can't afford to ignore. I learned this the hard way when my car kept emitting a gasoline smell from the filler neck. After extensive checking, I discovered the rubber seal on the cap had aged and deformed. The gasoline was evaporating rapidly, and I clearly noticed reduced mileage per tank. The worst part was during rainy days—water would seep into the tank through the gap, nearly damaging the fuel pump. The mechanic warned that even a small amount of water or dirt entering the tank could clog the entire fuel system, making the engine shake like it had a serious illness. Now, I make it a habit to regularly inspect the condition of the cap's seal. After all, replacing the fuel tank costs enough to buy dozens of new caps.
