Have Sugar In Your Gas Tank? Here’s What to Do

Written by

CarParts.com Research Team

Automotive and Tech Writers

Updated on November 7th, 2024

Reading Time: 4 minutes
Summary
  • Sugar won’t dissolve in gasoline. If someone puts it in your vehicle’s fuel tank, it won’t lead to the sugar caramelizing in the engine. Instead, the sugar will just accumulate at the bottom of your fuel tank.
  • Sugar sucked into the fuel system can clog the fuel filter and fuel injectors. This can cause engine-related symptoms.
  • Removing sugar from your vehicle’s gas tank typically involves cleaning the tank, the fuel filler hose, the fuel-sending unit, and the fuel lines.

There’s a myth that you can put sugar in someone else’s gas tank and ruin their car. This stems from the understanding that the sugar will dissolve in the fuel. Then, once the sugar-filled fuel is sucked into the engine, the heat will cause the sugar to caramelize, which will damage the engine. This idea stemmed from the 1950s when vandals used sugar to make engines malfunction. However, sugar simply clogged the mechanical fuel pumps at the bottom of the fuel tank, which stopped fuel from flowing to the engine.

What Happens If You Put Sugar In a Gas Tank

Sugar molecules can’t dissolve in gasoline because they have different molecular polarities. Sugar will just sink to the bottom of the fuel tank.

All the sugar won’t automatically get sucked into the fuel pump because the fuel sending unit pulls fuel through a small straw-like funnel rather than a drain-like hole. If there’s any sugar that gets sucked in, most vehicles are equipped with a fuel filter designed to remove impurities up to 10 microns in size. The filter can easily filter out the sugar since they’re usually around 100 to 400 microns in size.

A problem can stem from sugar clogging the filter. At the same time, there’s a chance some sugar can get past the filter and clog the vehicle’s fuel injectors.

The symptoms of sugar in a gas tank include: 

Modern vehicles use electric fuel pumps, which aren’t as prone to clogging. However, these pumps can still get clogged if there’s a lot of sugar.

Sugar in your vehicle’s fuel tank won’t cause extensive engine damage, but the fuel system and fuel injectors can develop issues if you continue driving your vehicle. Hence, you must remove the sugar from your fuel tank before driving your vehicle. 

The best action is to call a towing service that can take your car to a reputable mechanic. From there, the professional can remove the fuel tank and clean the sugar out of your tank and fuel system. That said, you can also do this task yourself if you feel confident in your DIY skills.

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How to Fix Sugar In Gas Tank

This process involves dropping your vehicle’s fuel tank, cleaning it, and replacing the fuel filter.

Raise the Vehicle

Raise the vehicle with a jack and mount the car on some jack stands. Ensure the battery is unplugged to eliminate the risk of sparks, which can ignite fuel vapors and cause a fire.

Access the Fuel Tank

Check your vehicle’s owner’s manual for information on accessing your vehicle’s fuel tank. On a sedan, the top of the fuel tank can be accessed by removing the rear passenger seats. You’ll see a lid, which can be removed with some screws.

You’ll be able to see the fuel pump on top of the fuel tank. You’ll need to pull out the fuel pump connector before disconnecting the fuel lines. Make sure to have a spare towel just in case fuel spills out. You need to press the tabs before you can pull out the lines.

Disconnect the Fuel Filler Hose

The fuel filler hose is a silicone tube that mounts to the side of the fuel tank. Removing this hose involves unscrewing the clamps that keep the hose connected to the opening.

Remove Fuel Tank Straps

The fuel tank is strapped to the vehicle’s chassis. These straps can be removed using screws or bolts. After removing the straps, the fuel tank just drops down. Be careful if the fuel tank is full of fuel, as it can be quite heavy.

Drain the Fuel Tank

Do this by tilting the fuel tank and draining the fuel into a bucket. Afterward, use a towel to soak up the remaining fuel.

Rinse the Tank

Use a hose to rinse the inside of the fuel tank. This will remove all the sugar granules in the fuel tank since sugar will dissolve in water. Dry the fuel tank afterward with the towel.

Clean the Fuel Hose

The fuel hose might also be filled with sugar. To clean this out, just use a hose to rinse the tube. Don’t be afraid to use a lot of water to ensure no sugar remains. Then, pour 99% isopropyl alcohol to rinse the tube. Any water in the tube will mix with the alcohol and cause it to evaporate quickly.

Replace the Fuel Filter or Pump Assembly

Replacing the fuel filter on some vehicles isn’t possible because their fuel filters are integrated with the fuel pump assembly. When this is the case, you’ll need to replace the entire fuel pump assembly. Some manufacturers recommend replacing the entire fuel pump assembly whenever the tank is contaminated.

Clean the Fuel Lines and Fuel Rail

Disconnect the fuel rail and fuel lines from the engine using a wrench. Once removed, use compressed air to blow the fuel line on the engine side. This will push the contaminated gasoline out the other end. Pour the fuel line with isopropyl alcohol to rinse it, then use pressurized air to push all the alcohol out. Do the same process for the fuel rail.

Remember that sugar in your gas tank won’t cause immediate catastrophic engine damage. That said, it can cause fuel system issues. If you think someone has vandalized your fuel tank with sugar, promptly address this issue. Otherwise, you might end up with further fuel system complications.

Written By CarParts.com Research Team

Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

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