How to Maintain Diesel Engines in Heavy Equipment

The Importance of Routine Diesel Engine Maintenance

Diesel engines operate under intense pressure and temperature. They are subject to substantial loads, and even minor neglect can lead to catastrophic failures. Regular maintenance ensures all systems function cohesively, reduces unplanned downtime, and safeguards your investment in heavy equipment.

Understand the Engine's Core Components

Before diving into maintenance protocols, it’s crucial to grasp the engine's fundamental components:

• Cylinder: Where combustion occurs.
• Piston: Moves up and down to convert combustion energy into mechanical motion.
• Crankshaft: Transfers the piston’s movement to the driveline.
• Camshaft: Times the opening and closing of intake and exhaust valves.
• Fuel Injector: Sprays diesel fuel into the combustion chamber.
• Glow Plug: Preheats air in cold-start conditions.
• Air Filter and Exhaust Valve: Ensure proper air intake and exhaust flow.

The Four-Stroke Combustion Cycle

Every diesel engine functions through a four-stroke cycle:

1. Intake Stroke – Air and fuel enter the cylinder.
2. Compression Stroke – Mixture is compressed, increasing pressure and temperature.
3. Power Stroke – Fuel ignites from compression, pushing the piston downward.
4. Exhaust Stroke – Spent gases exit via the exhaust valve.

Understanding this cycle helps operators and technicians pinpoint faults based on symptoms.

Scheduled Maintenance Intervals

Daily Checks

• Inspect coolant and oil levels
• Look for fuel or fluid leaks
• Check air filter restriction indicators
• Listen for unusual engine noise

Weekly Tasks

• Clean or replace air filters
• Inspect fan belts and pulleys
• Drain water separators in the fuel system

Monthly Service

• Test battery voltage and charging system
• Check glow plugs or grid heaters
• Inspect and lubricate linkage mechanisms

Quarterly Inspections

• Perform oil and filter changes
• Check fuel injectors for proper spray patterns
• Conduct compression tests on cylinders
• Inspect turbochargers and exhaust manifolds for carbon buildup

Vital Fluid Management

Monitor and replace as follows:

• Engine oil: Replace based on manufacturer specs or after 250-500 hours of operation. Contaminated oil loses viscosity and damages components.
• Coolant: Use the correct antifreeze mixture. Monitor pH levels to prevent internal corrosion.
• Fuel system: Diesel fuel must be clean and water-free. Drain water separators regularly.
• DEF (Diesel Exhaust Fluid): Ensure proper storage and fill levels for after-treatment systems.

Neglecting fluids can result in overheating, loss of lubrication, and premature wear.

Air and Fuel System Integrity

Blocked air filters reduce engine efficiency and increase fuel consumption. Check air filters daily and replace when restriction indicators suggest. Likewise, the fuel system should be tight and clean. Leaky injectors or clogged filters cause poor performance and smoking.

• Fuel Injector Care: Periodically inspect and clean injectors. Poor atomization leads to incomplete combustion and soot buildup in after-treatment systems.
• Air Intake and Turbocharger: Ensure hoses and clamps are secure. Clean the turbocharger housing and impeller blades as necessary to prevent imbalance and inefficiency.

Electrical and Ignition Systems

The ignition system includes the starter motor, glow plugs, and battery. A weak battery or faulty starter can delay starts and strain the engine. Glow plugs should be tested with an ohmmeter for resistance—replace if readings are inconsistent.

Prevent Overheating

Overheating causes warped heads and cracked blocks. Maintain the coolant system by inspecting the radiator, fan clutch, and water pump. Replace worn belts and hoses, and flush the cooling system per the equipment manufacturer’s recommendation.

After-Treatment Systems

Modern diesel engines come equipped with emissions control components like:

• EGR (Exhaust Gas Recirculation) systems
• DPF (Diesel Particulate Filter)
• SCR (Selective Catalytic Reduction)

Keep these systems clean and functioning. Forced regeneration may be required if the DPF becomes too clogged. Using high-quality diesel and avoiding extended idling helps reduce soot accumulation.

Operator Best Practices

• Warm up the engine before operating under load.
• Avoid extended idling to minimize carbon buildup.
• Do not overload the equipment—engine strain leads to overheating and premature failure.

Keep Your Engine Running Strong

From fluid checks and filter changes to system diagnostics and emission controls, every step matters. By following a consistent maintenance routine and educating your operators, you ensure longevity, efficiency, and reliability in the field.

For heavy equipment engine repairs in Somerville, NJ, reach out to Altus Equipment Company.