Fuel Filter Facts - Motor Werke

Replacing your fuel filter is an easy and vital part of keeping your car in top running condition. The fuel filter’s job is to prevent the fuel injection system (or carburetors) from becoming clogged. It is your car’s first line of defense against dirt build up in the engine. When filters become dirty or clogged, your car will be affected in several ways including fuel efficiency, performance and overall driveability.

When to Change Your Fuel Filter

Some fuel filters are meant to last the lifetime of the car, others require changing as often as every 19,000 km. The majority of vehicles require fuel filters to be changed on a regular basis. At Motor Werke we recommend replacement at minimum intervals of 40,000 km.

Driving conditions, type of car, and type of fuel all factor heavily into when filters should be changed. If your owner’s manual does not list fuel filter under the service maintenance schedule, you may have a non-serviceable filter (it may be an integral part of your fuel pump assembly inside the tank). Speak to your Motor Werke Service Team if you think this might be the case.

Regardless of what the manual says, if you experience any of the following, it’s time to check the condition of your fuel filter.

Your car stalls or idles rough
You car is difficult or slow to start
Your think your fuel may be contaminated
You experience decreased fuel economy
Acceleration is decreased or even sluggish
You let the fuel level in your vehicle drop below 1/4 tank on a regular basis

In-line Filters

In-line fuel filters are located in the fuel line between the gas tank and the fuel injector or carburetor. The in-line types come in many shapes and sizes and use a variety of different connectors, gaskets, hoses and clamps which are attached to the filter body at various locations and angles. Some filters have attached mounting brackets and fuel line supports. They can be made of metal or plastic.

Element/Cartridge Filters

Cartridge filters are installed in a housing in the car’s fuel system. The housing is generally located in the carburetor itself, and can also be found in or on the fuel pump or near the fuel tank. They can be made of pleated media, woven plastic and even porous metal.

Diesel Filters

Filters on diesel engines are usually made of steel, with a paper filter sealed inside the canister. Water settles to the bowl-shaped bottom of the filter and can then be drained off by opening a valve in the bottom of the filter bowl. Some filters have water sensors within the filter that signal the driver if moisture or condensation is present. Water in a diesel system is especially hazardous and the system relies on the diesel to lubricate the moving parts.

Tank Filters

Tank filters are located inside the fuel tank. They are a screen or mesh sock like apparatus that keeps big pieces of dirt and rust from being drawn into the fuel pump. Should the screen get clogged, it has the same effect on your car as a dirty fuel filter. Mini Coopers have a serviceable filter that is inside the fuel tank. Most in tank fuel filters will only be replaced when the fuel pump fails.

Replacing a tank filter is time-consuming. Fuel must be drained and stored in an approved container and your car battery must be disconnected to prevent any accidental sparks from electrical components.

When in Doubt …

If you are unsure if your vehicle’s fuel filter is in need of replacement, ask your Motor Werke technician. Cars that are driven on dirt roads, use gasoline with alcohol in it, or are over six years old may have rust or contaminants in the tank. Even something as small as sand or dirt falling into the tank while filling up can contribute to fuel filters not operating at an optimal level. When it doubt… call the Motor Werke Team for advice on your fuel filter and fuel system.