Q: Will letting fuel sit in a gas tank for over a year damage it or begin to rust it?

asked by on

The engine in my car started knocking so I parked it in my yard until I could get another motor for it. This October will be one year since the incident and right before it started knocking I filled the tank up with gas. Will leaving the gas in there that long damage the fuel tank or fuel system in any way? If so what do I need to do in order to get the fuel out?

Although it is dependent on storage conditions, ambient temperature and so forth, generally fuel that is older than 3 months should not be used in a motor vehicle. Fuel that is one year old is clearly unusable and will damage the fuel system, as you draw it into the engine, by plugging up components. Year old fuel almost definitely will not start the vehicle (i.e., will not burn because the volatiles have already evaporated). The fuel tank should be thoroughly drained and the inside visually inspected. If the tank has solid residues (gum and varnish), it is possible that the fuel pump pick up screen will be partially blocked. The fuel filter should be changed and the fuel injectors should be removed from the fuel rail and sent to a lab such as Mr. Injector for replacement of the tiny internal filter baskets (really tiny) in each injector and ultrasonic cleaning of each injector. If you want to avoid problems and minimize diagnostic headaches when you restart the vehicle the foregoing list is the absolute minimum required work. If you desire that any of these services be performed by a certified mechanic, please use YourMechanic’s services page to request and schedule service. If you have further questions or concerns as you decide what to do, do not hesitate to re-contact YourMechanic because we want you to make the most of your repair dollars and help you get the BEST possible results.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Will letting fuel sit in a gas tank for over a year damage it or begin to rust it?

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.