What Should I Do with Water in My Diesel Fuel?

When the diesel engine exhaust pipe out of the strange white smoke, start unusually difficult or even no response, experienced drivers or mechanic master mind will often tighten: diesel fuel mixed into the “water”? This is by no means a big deal. Diesel water problem is like an invisible killer, may trigger engine power drop, parts corrosion and even downtime failure.

1. Reasons for water in diesel fuel

The phenomenon of water in diesel fuel is the result of the interaction between the fuel system and the external environment. When the ambient humidity exceeds 80%, the condensation effect of the diesel tank breathing valve will form liquid water, especially in the day and night temperature difference of more than 15 ℃ in the region, the amount of condensation per day up to 0.5-1 liter. In addition, tank cleaning residues during oil transportation, container contamination during refueling operations, and improper blending ratios of some biodiesel can lead to moisture intrusion.

2. The danger of water in diesel fuel

Water in a diesel engine is not a trivial matter, and its destructive power can be fatal on several levels:

Power paralysis: water can not be compressed, but also can not be ignited like diesel. When the water with the fuel into the combustion chamber, will seriously interfere with or even interrupt the combustion process, the engine instantly lose power output, as being strangled throat.

Destruction of precision parts: The heart of modern diesel engines - high-pressure common rail system, fuel injectors and plunger coupling, its internal clearance is so small that it is measured in microns. The intrusion of water is like the introduction of tiny gravel, which will quickly cause these valuable parts to rust, strain or even completely seize.

Lubrication Failure: Diesel fuel has a lubricating effect. Water reduces this effect, increases metal-to-metal friction and multiplies the rate of wear.

Microbial growth: Water in the fuel tank provides a breeding ground for microorganisms. They multiply in large numbers to form sticky sludge, which not only clogs the filter, but also accelerates the corrosion of the fuel tank and pipelines by the acidic substances produced by their metabolism, forming a vicious circle.

3. Treatment

As soon as you realize that the diesel engine may have water ingress (e.g., white smoke, hard starting, sudden power drop, etc.), make sure to stop the engine immediately and perform the following key steps.

① Immediately shut down and cut off the source: This is the key point! Continuing to run will only pump more water into the high pressure system, causing irreversible damage. Decisively shut down the engine to allow the engine to completely cool.

② Lock the source of water, accurate investigation:

Check the fuel tank: Open the fuel tank cap and observe whether there is a clear separation of the water layer at the bottom (water is heavier than oil and sinks to the bottom). Use a special tank pumping tool or a clean long tube to carefully extract the liquid at the bottom for observation. On rainy days or after wading in water, especially check whether the seal of the fuel tank cover is intact.

Check the oil-water separator: Modern diesel vehicles are basically equipped with an oil-water separator. Locate it (usually in the engine compartment or sump), unscrew the bottom drain valve or just remove the catch cup to see if water is coming out. This is the most common and convenient initial point of judgment.

Trace the fuel supply link: Recall whether you have recently refueled at a suspicious gas station? Tanker trucks unloading fuel immediately after refueling easy to stir up impurities at the bottom of the tank water? Is the tank itself damaged or poorly sealed?

③ Thoroughly drain and clean the system:

Drain separator water: Follow vehicle manual guidelines for completely draining the oil/water separator of water and bottom contaminants. Some models require replacement of the entire filter element assembly.

Fuel Tank Sweep: If water is confirmed in the fuel tank, it must be thoroughly cleaned. The best course of action is to evacuate all residual fuel (water and dirty oil) and then rinse the interior repeatedly with a special tank cleaner or diesel fuel to ensure that no water or contaminants remain. Be sure to remove it cleanly!

diesel water is a problem that needs attention, timely detection and correct treatment, as well as do a good job of daily prevention, can effectively protect the stable operation of the engine, extend its service life.