Also known as “crankcase dilution”, mixing engine oil with diesel occurs because of internal leakage of the fuel injection system. If the diesel is not wholly burnt in the combustion chamber, it flows towards the crankcase, mixing with the oil present.
The inner walls, piston skirt, and segments are wiped away from any oil by the leaked diesel. The area is left without lubrication, leading to increased friction and wear and tear. Its causes may include a sealing ring failure, loose connections, extended idling periods, or faulty fuel injectors.
Understanding the various causes of engine oil mixing with diesel can give a helping hand in preventing the two components from mixing. Let’s discuss them further in the article below.
What Causes Engine Oil to Mix with Diesel?
Understanding the reasons behind the diesel-oil mixture aids in figuring out the solution. We shall discuss the causes below.
Poor Maintenance
Routine oil checks and changes can prevent fuel dilution by maintaining high performance of the parts involved in storing the oil. Hence, a lack of such regular checks leads to a slow build-up of fuel dilution. The assessments also help identify parts that need extra lubrication. Checking the fuel injector nozzles also helps in reducing the chances of fuel dilution. Dirty nozzles prevent the correct fuel atomization, preventing efficient and effective fuel combustion.
Failing Injector Nozzles
Normal wear-and-tear of nozzles leads to weakening the nozzles themselves, allowing diesel to mix with oil. The density of the sealing ring disappears on the nozzle itself which slowly allows fuel to pass through and mix with oil. Multiple failing nozzles will result in a higher mixture rate, leading to serious engine complications.
Engine Modifications
Some diesel engine modifications may alter smoke production or even increase its production. During combustion, the smoke passes through the crankcase before leaving through the exhaust pipe. The result is smoke passing through the oil, leading to contamination and dilution.
Wet Stacking
An engine that has not operated at optimum temperatures becomes cold, leading to complications and possible wet stacking. Colder machines possess lower combustion efficiency, causing the fuel to ignite further than expected during the compression stroke. Fuel flowing from out of the injectors tends to stick to the cylinder walls, slowly entering the system through the scraping of the piston rings and entering the crankcase.
Failing Diesel Pump Seals
The purpose of the seal is to prevent oil from mixing with diesel. Worn-out seals enable the flow displacement of either diesel or oil.
Cracked Cylinder Head
A cracked cylinder head is commonly found in vehicles with aluminum engine blocks. The cracks are caused when a torque wrench is not used to tighten the nozzles; instead, a generic tool is used. The gaps allow diesel to flow through and mix with the oil.
High-Pressure Pump Parts
Damaged gaskets of the high-pressure pump enable diesel to mix with oil. At times, the plungers may also fail in delivering sufficient pressure, making diesel enter the pump and mix with the oil. Such occurrences happen in older engines.
Signs of Diesel-Engine Oil Mixture
The signs and symptoms of engine oil mixing with diesel are easy to identify even to the untrained eye. Curbing these signs will help to prevent further mixing of the components.
Increase in Fuel Consumption
When the engine is faulty, diesel will leave the tank and semi-combust, mixing the remaining amount with the oil. The lack of burnt fuel affects the engine’s performance, causing a higher fuel intake. The result is an engine that constantly consumes more fuel but burns equally.
Drop in Engine Performance
Unlike petrol engine oils, irregular diesel combustion affects the engine’s performance. Some of the diesel does not combust, instead making its way into the oil reserves and mixing with it. The contaminated oil cannot lubricate properly, leading to wear-and-tear and decreased performance.
Dark Exhaust
A dark color characterizes the color of the mixture between diesel and engine oil. When the engine runs and dark smoke is produced from the exhaust, it is a clear sign of a diesel-oil combination.
Overheating
Engine oils can also act as a coolant in some engines. If the oil is mixed with diesel, some cooling properties are eliminated, leading to engine overheating.
Solutions to Prevent Diesel-Engine Oil Mixture?
After identifying the causes and signs of a diesel-engine oil mixture, finding the solution is the next step. There exist several solutions that aid in preventing the mixture from occurring as well as improving the engine’s performance. The ways are briefly discussed below.
Do Regular Checks
Maintaining routine engine checks goes a long way in preventing engine oil from mixing with diesel. A person can detect whether diesel has combined with the engine oil and make the necessary corrections to fix the issue. Regular checks also help in spotting any deformities in the engine.
Operate Engine in Optimum Temperatures
When an engine remains idle in a cold environment, it tends to slow down its performance. Operating in optimal temperatures that offer high fuel combustion is a sure way to prevent diesel-engine oil mixture. Using a diesel engine oil like the ITR Supremo XD helps in optimum operation.
Fewer Modifications
Applying minimal modifications to your engine helps in reducing the chances of diesel mixing with engine oil. The improvements may alter how combustion works, leading to engine damage and eventually diesel-engine oil mixture.
Replace Worn Out Parts
Worn-out engine parts directly affect its performance. In addition, the components may also allow diesel to flow into the oil reservoir due to their weakening properties. Replacing such crucial parts simplifies engine operation and prevents engine oil mixing with diesel.
Appropriate Tool Use
A torque wrench is the best tool for any engine use. It is designed to specifically handle any engine-related issues. Using any other device, especially in tightening, will lead to complications and damage to the engine.
Conclusion
The purpose of engine oil is to maintain lubrication and optimum engine performance. When mixed with diesel, the oil loses its lubrication properties, resulting in poor engine performance. Periodic routine oil checks lead to further diesel-engine oil mixture, hindering operation and engine lifespan reduction. Measures like regular checks and engine parts replacement prevent diesel from mixing with engine oil.
ITR Lubricants are known for the best diesel engine oil for motor cars. We offer top-notch engine oil and lubricants for diesel and petrol engines, tractors, hydraulic machines, etc. ITR Lubricants are an ISO-certified company with over 50 years of operation. Italian engine oil production technology is used to manufacture oils and lubricants. Get a quote for engine oil mixing with diesel.