A car’s gas tank is a vital component that allows you to fuel up and drive wherever you need to go. However, there are several things that can damage a gas tank over time and cause potentially hazardous situations. Understanding what can harm your gas tank will help you take steps to protect it and know when repairs or replacement may be needed.
Rust and Corrosion
One of the most common causes of gas tank damage is rust and corrosion. Gas tanks are typically made from steel or aluminum, which can corrode when exposed to water, salt, dirt, and other contaminants. Road salt, humidity, and condensation are common causes of rust on the outside of a tank. Meanwhile, water that makes its way into the tank can cause corrosion on the inside surfaces.
Rust causes the metal of the tank to degrade and form holes or leaks. Small leaks may go unnoticed at first, leading to fuel vapors escaping the tank. Large holes or fractures can lead to fuel spilling out onto the ground. Both situations are hazardous and make driving unsafe.
Preventing Rust Damage
Here are some tips to help prevent rust damage to your gas tank:
- Wash the undercarriage of your car regularly to remove dirt, salt, and grime that causes rust
- Have the tank inspected for rust periodically and re-coated if needed
- Ensure the tank is properly sealed so water cannot get in
- Fix small leaks or rust spots right away before they get worse
- Replace the tank at the first signs of extensive rust or corrosion
Dents and Physical Impacts
Dents, punctures, cracks and other physical damage can also occur to a gas tank. Impacts from debris on the road, accidents, or improper modifications or repairs can harm the structural integrity of the tank. Even small dents near seams, fittings or bends in the tank can expand into fractures. Physical damage to a tank will often require replacement of the entire tank for safety.
Avoiding Physical Impacts
Some ways to help avoid dents, cracks and punctures include:
- Driving carefully over debris or bumps in the road
- Keeping the tank protected underneath the vehicle, not behind exposed tow hitches or low-hanging modifications
- Having qualified mechanics perform any repairs or modifications that could impact the tank
- Checking the tank skid plate regularly and replacing if damaged
- Checking the tank straps and supports are tight and in good condition
Improper Fuel Mixtures
Putting the wrong type of fuel into your gas tank can also lead to damage over time. Gasoline engines are designed for unleaded fuel. Filling up with leaded gasoline, diesel, or other mixtures can negatively impact the engine and fuel system.
The wrong fuel can corrode and degrade rubber hoses and seals in the fuel system. It can also clog fuel filters and injectors. In some cases, the engine may not run properly or fail to start with the wrong fuel mixture in the tank and lines. Draining and thoroughly flushing the tank may be required to correct the issue.
Avoiding Wrong Fuel Damage
- Never pump the wrong type of fuel into your vehicle
- Check the fuel type before refueling – don’t rely on the pump color or other indicators
- Never mix different fuel types in your tank
- Add fuel additives sparingly and only as recommended
Sugary Fuel Contamination
Sugary substances accidentally introduced into the gas tank is another hazard for damage. Sugar is soluble in gasoline. If sugar gets into the tank, it can flow through fuel lines and clog filters, injectors and sensitive engine parts. Common sugary contaminants include:
- Alcohol mixtures like ethanol gas
- Raw sugar accidentally added to the tank
- Sweetened beverages that spill into the tank
- Maple syrup, molasses or other sugary substances added in error
To fix a sugary contamination problem, the fuel tank, lines and filters will need to be drained and flushed thoroughly. Soaked filters will need replacement. In severe cases, injectors may need cleaning and engine parts may be damaged.
Preventing Sugar Contamination
Taking precautions can help avoid potential sugar contamination issues:
- Never put sugars or sweet drinks directly into the gas tank
- Use only the recommended ethanol gasoline blends for your vehicle
- Don’t overfill the tank which can cause spitback into the fuel filler
- Make sure the filler cap seals tightly to avoid foreign matter entering
- Avoid using food containers to transport or store gasoline
Chemical Contaminants and Additives
Certain chemical contaminants and fuel additives can also lead to gas tank damage when used improperly or excessively. Some examples include:
- Too much fuel injector cleaner
- Oil or other motor fluids accidentally added
- Brake fluid or coolant spilling into the tank
- Diesel exhaust fluid (DEF) added to a gasoline engine
- Gasoline with too much ethanol for your vehicle
As with sugary contamination, chemical issues require draining and thoroughly flushing the fuel system to correct. Filters, injectors and other components may also need replacement if they are damaged.
Preventing Chemical Contamination
You can help prevent chemical contamination problems by:
- Using fuel additives sparingly and only as recommended
- Not mixing oil, coolant, brake fluid or other chemicals into the fuel tank
- Checking the ethanol percentage before refueling
- Not using DEF in a gasoline engine
- Making sure the fuel filler cap seals tightly
- Addressing any leaks from other engine fluids immediately
Fuel Tank Deformation
Long-term deformation of the gas tank is another potential problem. Over many years, the constant expansion and contraction of the tank from filling up and driving down the fuel level can cause deformation. Metal tanks can bend and flex slightly over time. Deformation accelerates with rust damage.
Initially, minor tank shape changes may not cause issues. But progressive deformation can lead to cracks, difficultly properly fueling up, and improper fuel gauge readings. Once deformed significantly, the only remedy is to replace the compromised gas tank.
Avoiding Tank Deformation
You can maximize the lifespan of your gas tank and reduce deformation chances by:
- Not overfilling or running the tank to near empty repetitively
- Following fuel octane recommendations – low octane can increase heat and pressure cycles in the tank
- Keeping the tank properly supported on the straps or saddles
- Replacing the tank at the first signs of deformation or cracks
Gas Tank Expansion and Contraction
The gasoline inside the tank also expands and contracts slightly as temperatures change. This thermal expansion and contraction occurs daily as well as seasonally with temperature swings. Over years of heating and cooling cycles, the fuel tank metal will fatigue. This can eventually lead to cracks, leaks, and other damage.
Thermal cycling degradation is difficult to prevent entirely, but keeping the tank full as much as possible helps minimize the empty space the fuel can expand into. Parking in the shade also helps reduce temperature swings. Replacing aged tanks proactively can avoid cracks from thermal fatigue.
Internal Lining Degradation
Some vehicle manufacturers apply protective internal linings inside the gas tank to prevent corrosion and help seal the surface. Epoxy phenolic resins are common tank linings. However, these coatings can degrade over time from sustained exposure to fuel and thermal cycling. As the lining breaks down, it can flake off and clog fuel system components. Bare metal underneath will be exposed to corrosion.
Unfortunately the internal lining cannot be repaired or reapplied without removing and replacing the entire fuel tank. Maintaining a full tank and limiting temperature fluctuations helps maximize lining life. But degradation will occur eventually in older tanks. Replacement of aged tanks prevents issues from deteriorating internal coatings.
Fuel Pump Problems
Issues with the in-tank electric fuel pump can also lead to gas tank damage in some cases. Fuel pump problems include:
- Pump failure allows the tank to run dry, causing overheating and fire risk
- Leaking pump seals allow fuel to escape into the tank
- Electrical short circuits can melt pump components or ignite fuel vapors
These conditions can damage the pump itself as well as the interior of the tank and associated components. Fuel pump problems should be addressed immediately to avoid catastrophe and preserve the tank.
Avoiding Fuel Pump Damage
Some fuel pump best practices include:
- Listening for signs of a failing pump like whining noises or poor engine performance
- Replacing the pump at the first signs of failure
- Keeping the tank over 1/4 full at all times to avoid pump overheating
- Having the pump inspected or replaced periodically for preventative maintenance
- Addressing any check engine lights or performance issues promptly
Conclusion
Gas tanks are susceptible to many forms of damage over time. Rust, physical impacts, contamination, component failures and general wear can all take a toll on your fuel tank. Careful driving habits, proper maintenance, and proactive replacement of aged tanks are key to maximizing lifespan and avoiding hazards related to gas tank damage. Be alert for any symptoms of failure and address fuel system issues promptly to help keep your gas tank in safe working condition.