1989 Toyota MR2 - Fuel Water Separator Valve

What is a Fuel and Water Separator Valve?

A fuel and water separator valve is a component in a diesel vehicle's fuel system used to separate water and contaminants from the diesel fuel before it reaches the engine. Diesel fuel naturally absorbs water over time from condensation in the fuel tank, which can cause engine damage, reduce fuel efficiency, or lead to corrosion in the fuel system. The water separator valve or petcock allows the water that is collected by the fuel filter or water separator to be drained. Along with draining the water, fuel filters should also be replaced regularly to keep the fuel clean and the diesel engine performing its best. If you notice the fuel filter is clogging faster than it should, or if there is more water than usual in the fuel mixture or water separator that is causing performance or fuel pressure issues, then inspect the fuel-water separator valve and replace it if needed. Inspecting the fuel and water separator valve and fuel filter, as well as ensuring that all air is purged and water is drained from the system, can help keep your diesel vehicle running at its best. For your next diesel fuel filter replacement, shop O'Reilly Auto Parts' selection of fuel filters, water separators, or fuel-water separator valves for most diesel vehicles.