Water In Diesel Fuel Systems

Water in diesel – major cause of failures in modern diesel cars.

With CRD fuel systems found on current vehicles, water in the fuel is causing some large repair bills.

When I say large, I mean budget breakers.

How about $10,000 to $20,000 bills?

Rust formation can occur very quickly when water is introduced to the system and rust particles cause rapid wear to the diesel pump and injectors due to the abrasive nature of rust particles. Diesel fuel lubricates the high pressure pump but if water gets to the pump, lubrication is impaired, resulting in wear of pump components.

Rust further exacerbates this wear. Water of course should not be present in diesel fuel. However, it is difficult for fuel outlets in Australia to ensure the diesel fuel is free of water. When a tanker delivers a fresh fuel load to the service station, water at the bottom of the tank gets stirred up, mixing with the diesel fuel and allowing water to be pumped into your fuel tank – sometimes many litres of water.

A modern diesel engine consumes only a small portion of the fuel it draws, the rest of which circulates back to the tank. Fuel water separator traps (as used by Water Watch) help in removing the water content by separating water from the fuel in every cycle together with any particles heavier than the diesel.

Fuel Water Separator

Research indicates that in high pressure fuel systems typical of common rail, mechanical filtration is extremely difficult, dispersed and emulsified water cannot always be captured or detected by even the most advanced filter systems. Filters are designed for particles not fluids.

Modern common rail systems are typically equipped with a “Water In Fuel” warning light to alert operators to the presence of free water, but those warning lights are not activated by untreated emulsified water (commonly found in motor vehicles).

Water Watch removes 99.8 per cent of free water and will detect and alarm if there is free, dispersed or emulsified water in the fuel.

Secondary, filters cause a restriction to fuel flow in Common Rail Diesel vehicles because the filter medium is an additional physical barrier that the system has to pull fuel through and the CRD system relies on the correct pressures to operate.

Placing a secondary filter on a vehicle is a duplication of the OEM filter already on the vehicle – which has proved to provide little protection against water damage in the CRD fuel system.

Water Watch

There is a precision aftermarket water trap/separator known as Water Watch that detects a very small quantity of water before it enters the OEM filter.

Water Watch separates and removes both water and particles from the fuel flow, especially in high pressure CRD systems, further into alerting the driver that water is present in Water the vehicles fuel.

The separator assembly removes and holds water and particles below the fuel flow ensuring that it goes no further into the fuel system. The advantage of Water Watch is that there is no filter medium, so there’s no restriction to the fuel pressure in the CRD system.