How to Unclog a Clogged Fuel Tank Vent Pipe?
2 Answers
When the fuel tank vent pipe of a car becomes clogged, you can try to unclog it by inserting a sturdy plastic pipe into it. If this doesn't solve the problem, it is recommended that the car owner visit a 4S shop or an auto repair shop to have it handled by professionals. Below is some extended information about the fuel tank: 1. The vent hole of a car's fuel tank is located on the fuel tank cap. There are two valves on the fuel tank: an air valve and a steam valve. When the fuel pump draws fuel, the pressure inside the tank decreases. When the pressure drops below 98 kPa, the air valve opens to allow air into the tank. Since gasoline is volatile, when some of the gasoline in the tank vaporizes, it increases the pressure inside the tank. When the pressure reaches 120 kPa, the steam valve opens to release gasoline vapor, which is not directly emitted into the atmosphere but passes through the activated carbon canister to the intake manifold and is eventually discharged through the exhaust pipe. 2. If the car engine fails to start after refueling, or if the car jerks while driving, it may be due to an overfilled fuel tank. Once the vent hole is clogged, negative pressure can form inside the tank, leading to poor fuel supply or even a complete lack of fuel. When refueling, it's sufficient to stop when the fuel gun automatically shuts off, and no additional fuel should be added. However, if the fuel level in the tank is consistently too low, it can affect the cooling of the fuel pump and shorten its lifespan. It is recommended that car owners refuel when the fuel gauge indicates a remaining fuel level of 1/4.
I've encountered the issue of a clogged fuel tank vent pipe several times, and experience tells me to start with the simplest approach. Park the car and locate the vent pipe, usually a soft tube near the fuel tank. You can use a compressed air gun or bicycle pump to gently blow air into the pipe opening, being careful not to use too much pressure to avoid damage. If blowing doesn't clear it, remove the pipe and carefully poke through it with a thin wire, then rinse away dirt or insect nests with soapy water. I've done this myself, and the results were quite good while saving money. Clogs often occur due to accumulated dust or debris, which can cause fuel to spray out during refueling or create strange odors in the car. If you're unsure about handling it yourself, it's best to visit a repair shop where mechanics have professional tools to avoid damaging parts. Regularly check the pipe during maintenance to prevent similar issues.
