The Four Symptoms of a Bad Toyota Sienna Fuel Tank Cap
The fuel tank cap in your Toyota Sienna is a simple but very important device. If problems develop with it, you run the risk of decreased engine performance, fuel wastage, and poor gas mileage. You should check your fuel tank cap for proper function every time you visit the gas station. These are the four symptoms you ought to know about bad fuel tank caps.
The scent of gas
Gasoline is a volatile material that when exposed, it usually travels quickly in the air. The most evident sign of a fuel tank cap that has been tampered is a lingering smell of gasoline. An improperly sealed gas cap can cause this. However, this doesn't happen frequently. Be sure to check other parts like the gas tank or the fuel line for leaks.
Again, due to the highly volatile nature of gasoline, it evaporates very easily. If your fuel tank cap is leaking gas or is not sealed properly, the fuel in your tank may evaporate at a surprisingly alarming rate. If you notice a sudden decrease in fuel efficiency and you couple that with the strong smell of gasoline hovering in and around your vehicle, check your fuel tank cap and other fuel related parts.
"Check engine light" is on
Normally, vehicles like your Toyota Sienna are equipped with a check engine light that may illuminate for a myriad of reasons. Figuring it out will be a tough nut to crack. One of the obscure causes for this light to come on could from a defective fuel tank cap.
Cars that drive around with a bad fuel tank cap may emit harmful waste products such as smog. Smog is a mixture of unburned fumes that aren't properly combusted and filtered through the engine and exhaust systems. A bad fuel tank cap may contribute to this problem because openings in it may allow contamination of the fuel. Once the fuel becomes contaminated with foreign material, the combustion process might get disturbed. For one, water could get into the engine through a fuel tank cap with a damaged seal. This will usually form a misfire. Over time, repeated misfires will cause permanent damage to your engine.