How to Clean Your Fuel Tank

Your gas tank is dirtier than you think. It’s loaded with contaminants from:

  • The fuel you put into it
  • Dust/dirt in the air
  • Corrosion of your car’s fuel system

Old Gas StationMost contaminants come from fuel sitting in dirty gas tanks at gas stations. Photo credit: Steve Mays

Why You Should Clean Your Gas Tank

There’s no way to prevent your car's fuel tank from getting dirty, but you should clean it at least once every few years. It’s actually a smart way to maintain your car because it:

  • Helps keep your fuel economy up
  • Extends the lifespan of your fuel system
  • Prevents the fuel injectors and fuel filters from getting clogged
  • Lessens the risk of premature fuel pump failure

Another way to maintain your car is to run a fuel system cleaner through your car’s fuel system once or twice a year. (Learn more about fuel system cleaners here). It won’t entirely clean your tank, though, so a fuel tank cleaning is still in order.

There are two ways to do it:

Professional Steam Cleaning

Some radiator shops and pressure washing companies offer steam cleaning services for fuel tanks. It’s a great way to restore your fuel tank to the pristine condition it was in before your car left the dealer lot. A steam cleaner loosens the dirt and sludge stuck on the sides and makes the tank easier to wipe down. The end result of a good steam cleaning job is astounding; your fuel tank will likely look brand spankin’ new.

Businesses performing steam cleaning services will also recondition your tank and check for cracks or leaks. Such a service is pricey, though. There’s a cheaper alternative, and it’s to clean the tank yourself.

DIY Cleaning

When you clean your fuel tank at home, you need the following:

  • Dish soap
  • Water
  • A clean approved container or fuel caddy big enough to hold the fuel
  • A siphon
  • A lint-free towel
  • Lots of elbow grease

Safety Tips

Before starting, take your own safety into consideration:

  • Make sure there’s a working fire extinguisher nearby
  • Avoid smoking or working near anything that could ignite fuel, like pilot lights or incandescent light bulbs
  • Keep the fuel container away from anything that could ignite it, knock it over, or contaminate the fuel.
  • Wear safety glasses and gloves
  • Work in a well-ventilated area
  • Clean up any spills immediately
  • Always relieve fuel pressure before opening your tank

9 Steps to a Clean Fuel Tank

  1. Remove the fuel tank from your car and then swish it around. You want to free up as much debris and sludge as possible from the sides of the tank to save yourself the headache of scrubbing it all out later in the process.
  2. Clean off the debris from the outside of the tank with a rag or compressed air.
  3. Remove the lock ring and any remaining fuel lines from the fuel pump, which is located at the top of the tank.
  4. Remove the fuel pump. You might need to jiggle the top a little bit to get it to come out. At this point, fuel may leak out so be sure to have a few rags nearby to clean up any spills right away.
  5. Siphon out the remaining fuel in the tank and store it in the approved container or fuel caddy.
  6. Scrub the inside of the tank with soap and water. If you have access to pressurized water, use it. Drain the water when you’re done.
  7. Dry the inside of the tank with a lint-free towel or compressed air until completely clean and dry.
  8. Pour the fuel back into the tank (see below for more information on how to do this properly).
  9. Put the fuel pump back on (or a new fuel pump, if you have one) and then put the tank back on the car.

What to Do With the Fuel

You might be wondering why you’d put dirty fuel right back into the tank after you’ve cleaned it. That's why you need to filter it first. If filtered properly, the fuel you put back into your clean tank will no longer be contaminated.

Fuel caddies come equipped with two-way filters that will filter out the dirt and debris when you pour the fuel into and out of it. So you don’t have to worry about putting dirty fuel back into the tank when you’ve got one of those things.

What about when you’re using a regular ol’ container? How will you filter the fuel?

Three words: fuel filter funnel. Put a funnel into the opening when pouring the fuel back into the tank and it will filter out the water, dirt, and debris. A fuel filter funnel costs about 20 bucks, and it’s worth every cent.

Car gas pumpPhoto credit: Wisconsin Department of Natural Resources

After you clean your fuel tank, you’ll enjoy better mileage and a smoother ride. You should notice the difference right away, especially if you haven’t had your car’s fuel tank cleaned in years.