The Effects of Diesel Fuel Contamination
Not only can these failures be extremely costly to repair, but these catastrophic failures can be dangerous, especially when they occur on the road or at high speeds.
Fortunately, many of these failures can be prevented through preventative solutions such as a dependable Fuel Management Solution.
Let's take a look at the symptoms, causes, testing, and solutions for diesel fuel contamination.
Symptoms of Fuel Contamination
Don't Ignore Your Engine Check Light
Many people have been or have known someone that was in a situation where the “check engine” light comes on in their vehicle out of seemingly nowhere. Anxious at first, they tone down their driving to see if they can feel any difference in how the vehicle is running.
Strangely enough, it doesn’t feel any different than before- so they convince themselves it probably isn’t anything other than the truck being a bit “finicky”.
At first, a few days go by and then a few months. The light is still on and since the vehicle doesn’t feel to be running any different, it’s running just as often and hard as it normally would.
However, under the hood, components are not operating as designed and the continuous operation of worn parts is damaging the very systems that keep the vehicle running.
At this point, detrimental engine failure could be just a matter of time,
Clogged Fuel Filters
Frequently clogged fuel filters are oftentimes one of the first initial signs of possible diesel fuel contamination. The filter is designed to capture particles in your fuel before they pass into the engine and these pieces of matter can be made up of clumps of sludge, metallic particles, or other unwanted particulates.
If a fuel system is experiencing an atypical recurrence of fuel filter replacements, the problem’s root could lie in the quality of the fuel being supplied to the filter.
Heavily contaminated fuel would consistently provide particulates and other undesired materials that quickly clog filters, possibly leading to other issues in the fuel system.
This contamination could be stemming from either the fuel source itself or from the internal corrosion of the very fuel tank being used to fuel the engine.
Failing Fuel Pump
With frequent fuel filter clogging, fuel pump failure is often to follow. Because of the restriction caused by the clogged filters, the fuel pump could be working harder than designed to deliver fuel from the tank to the engine.
While a fuel pump is failing, the fuel pump will not be able to deliver a steady flow of fuel, interrupting the mechanical stroke and function of the engine. This can be especially noticeable under acceleration, where fuel demand is increased however the fuel pump is unable to deliver the fuel at the requested rate.
Symptoms of a failing fuel pump may include:
· Jerks or sputters at high speeds
· Power loss on acceleration
· Power loss while driving up a slope
· Power loss while towing
· Engine surging while acceleration is not engaged
· Engine will not fire
When a fuel pump is exerted to the point of failure, it is past the point of simple maintenance to get the engine running again. When a fuel pump fails, fuel line pressure is lost thus not being able to deliver any fuel for the engine to fire up. Downtime of equipment for major repair is expected at this point to get the fuel flowing properly again.
The above diagram explains how combustion in a diesel engine is achieved. During the combustion cycle, fuel is injected into the cylinder and ignites, creating the energy needed to transfer to the mechanical output that drives the vehicle or equipment.
Diesel fuel injectors are designed with specific functional tolerances as per the truck’s manufacturer. If these injectors begin to fail or veer from the designed tolerances in any way, then the fuel spray trajectory within the combustion chamber is drastically affected.
Catastrophic Engine Injector Failure
When catastrophic engine injector failures are experienced, the engine fails to continue operation due to these sudden occurrences. Typically, these experienced events can only be restored through costly repairs that often result in prolonged equipment downtime.
Operations and equipment managers rely on proper equipment functionality to maintain revenue margins and business profitability. It is for these reasons that attention should be directed at managing, predicting, and preventing these failures from occurring through proper equipment maintenance and operation.
Equipment specialists and OEMs typically operate their equipment around recommended maintenance procedures that are designed to limit component failure and prolong equipment life.
It is common for OEMs to recommend these maintenance procedures to uphold warranties. Fuel injector replacements are a critical component to these OEM warranties, with recommendations often being at the engine’s half-life. Using contaminated diesel, shortens the time before an engine is considered to have reached half-life.
Although equipment maintenance personnel are responsible for managing engine equipment and remediating potential issues, not all can be predicted and/or prevented. This is often the case with contaminated fuel, as operations managers are often not aware of the quality of the fuel they are procuring or filling up with enroute.
With the use of contaminated fuel, erosion of the injector valve seat is likely, resulting in a partial functional failure that will eventually lead to a full functional failure of the fuel injector valve.
The Failure Chain Reaction
· Contaminated fuel is sent through fuel injectors
· Fuel injector valve deterioration begins
· Fuel pressure through injector nozzle reduces
· Fuel volume through the injection system reduces
· Engine ECU increases fuel load to compensate
· Reduced fuel atomization
· Soot generation within the cylinder
· Emissions increased
· Experienced power loss
· Partial injection failure point
· Injector wear continues
· Fuel consumption increases dramatically
· Visible and audible signs of engine distress
· Full injection failure
To recap: Fuel injector nozzles are designed to spray a mist of fuel into the cylinder for piston compression and fuel combustion through precise inlets. When injector tolerances have been compromised, fuel droplets from the injector nozzle may not be able to achieve complete combustion, often resulting in smoke and soot emissions.
If the issue is not addressed, soot will build on the injector tips and eventually cause blockages. These blockages can also occur within the engine valves, cylinder walls, and exhaust system and lead to catastrophic engine failure.