What causes fuel contamination?

What causes fuel contamination?

Fuel contamination and water in fuel can result in serious vehicle driveability concerns, such as damage to the vehicle's fuel system and engine.

Fuel contamination can occur as the result of vandalism or accident, but fuel contamination also occurs naturally, based on environmental factors. Accidental contamination in fuel could occur from water entering a gas station's underground tanks following a flood or poor quality fuel being delivered to the gas station. Fuel quality also can deteriorate naturally as part of the ageing process as fuel additives evaporate and chemicals change properties.

Regular vehicle use, proper fuel storage, and regular diesel fuel system maintenance are often sufficient to prevent most fuel contamination concerns.

Gasoline-powered vehicles

If you are experiencing starting, rough idle or hesitation driveability problems during a cold start, try a different brand of unleaded gasoline. If the problems persist, see your authorized Ford Dealer. Do not add aftermarket fuel additive products to your fuel tank. It should not be necessary to add any aftermarket products to your fuel tank if you continue to use high-quality fuel recommend in your Owner's Manual.

Diesel-powered vehicles

Diesel fuel and bio-diesel fuels are especially susceptible to environmental factors, and they have a chemical attraction to water molecules. As a result, diesel-powered vehicles have a water separator and a unique fuel filter to reduce water from passing through the fuel system. Diesel engines use extremely high pressures to inject fuel into the engine. Water in the fuel compromises fuel lubricity and causes corrosion of fuel system components, which could lead to the fuel system or engine damage. Diesel owners are encouraged to:

  • Maintain your Ford diesel vehicle with Motorcraft® filters for the best vehicle performance.
  • Drain the water separator monthly or when the 'Water in Fuel Lamp' illuminates.
  • Motorcraft® Cetane Booster & Performance Improver can be added to improve fuel economy, starting ability, and reduce engine wear.
  • To avoid fuel gelling in cold weather, add 177ml of Motorcraft® Anti-Gel & Performance Improver to every new tank of fuel.
  • If using bio-diesel fuel, do not exceed the recommended bio % as explained in your Owner's Manual.

Fuel system damages and repairs

Your local Ford Dealership has technical resources available to diagnose fuel system concerns, determine warranty coverage, and make necessary repairs. Careful consideration is taken to confirm the source of the fuel system or engine damage. If it is determined that fuel contamination or water in the fuel is the cause of damages, you will be responsible for completing the necessary repairs.

d8c07f3a-2d0d-4b7e-98eb-c6f3687c61b2.png Note: Fuel contamination or environmental factors are not covered repairs under Ford Motor Company of Canada warranties.

Customers who believe that their fuel quality was compromised due to no fault of their own, should contact the fuel supplier and check their vehicle insurance company for coverage.


Motorcraft® is a registered trademark of Ford Motor Company.