Why Your Diesel Won't Start: The Truth About Fuel Gelling Up

Diesel engines are characterized by their reliability, their use of torque, and the fact that they can handle a heavy workload, which makes them highly sought after in heavy machinery, large trucks, and vehicles. But in colder months, lots of diesel owners encounter a frustrating issue: the engine will not start, or it is hard to start. Knowing the reason behind the occurrence of this and how it affects the engine can spell the difference between having a smooth winter riding and having to be bailed out on the roadside in a cold winter. 

Science of Temperature and Diesel Fuel 

Diesel fuel contains hydrocarbons as sources of energy when burnt, and one of these important hydrocarbons is paraffin wax. It is a wax that would be dissolved in the fuel under normal conditions and provide great help in providing lubricity and efficiency in the engine. Under ambient temperatures, however, the temperature is below a certain limit, and hence the wax starts crystallizing out of the liquid part of the fuel. Then wax crystals merge, creating a thick substance which obstructs the fuel lines, filters, and injectors. This transition between a free-flowing liquid to a gel-like substance is what leads to diesel engines having problems starting up when they are cold or even stalling as well.  

External Conditions That Speed Gelling 

Temperature is the main aspect that causes diesel fuel to gel, and there can be several other external conditions that contribute to the process and make it more intense. High humidity and moisture in the fuel system can make the situation worse since the water droplets can freeze and block the system along with the wax crystals. The fuel type of diesel that is used also contributes, as summer-grade diesel that is prepared to handle warmer temperatures is formulated to gel over a higher temperature than diesel that is prepared to face colder temperatures.  

The Importance of Prevention and Fuel Additives 

Prevention of gelling begins with action before temperatures drop to prevent gelling. Diesel fuel additives are quite important in being able to change the properties of the diesel so that it can withstand low temperatures. With the right choice of additive and using it at the right concentration, a significant difference will be made in the prevention of engine failures during winter. You can buy a high quality product that prevents diesel fuel from gelling up that helps you to remove gel easily and efficiently. Severe contamination with water is also known to contribute to gelling thus frequent maintenance of the fuel such as changing the fuel filters would also be beneficial in preventing gelling.  

Indicators That Fuel Has Already Gelled 

Early detection of signs of gelling will help in working on the condition before it becomes a major menace. Cloudy fuel is one of the earliest signs, and it means that the formation of wax crystals has begun. High levels of difficulty in starting the engine, jerky idle, and sudden loss of power during driving are also very great signs that the fuel is about to gel. At worst, the engine might not ignite, and the fuel system can be clogged off. The other indicator is low fuel pressure that can be detected on most occasions with the help of diagnostic tools. When the car shows such symptoms in cold-weather conditions, fuel gelling is most probably the root cause of the problem.  

Handling Fuel that leaves it takes when it happens. 

When diesel fuel has already gelded, the issue at hand becomes putting the fuel in a usable condition. The best way to do this has been known to be by increasing the temperature of the fuel system to such a point that the wax crystals are melted once again into the liquid fuel. This is achievable through the transport of the vehicle in a heated area or utilization of heaters specifically fitted on the fuel line and tank. There are emergency additives that can be used in breaking up wax crystal blockages to restore fuel flow, but those take time to move through the system.  

Conclusion 

Cold weather can be an unruly opponent to diesel engines, and you cannot start the engine in freezing temperatures often due to the characteristics of the fuel. Diesel fuel has properties that can be advantageous under normal temperature conditions, but not ideal during low temperatures. When the wax crystals grow and merge, the fuel enters a gel-like state, which prevents the flow required for an engine to operate. Solving this problem not only means that the diesel engines have been kept in difficult conditions but also safeguards the general health of the fuel system.