Terex TC16 with Mitsubishi L3E Engine: Poor Starting Troubleshooting

[MikePhua]

Introduction
The Terex TC16 is a mini excavator equipped with a Mitsubishi L3E engine, known for its reliability and efficiency. However, some users have reported issues with poor starting performance. This article discusses the possible causes of the problem and provides troubleshooting tips to help diagnose and resolve the issue, ensuring that the excavator operates smoothly.
Common Causes of Poor Starting in the Mitsubishi L3E Engine

1. Battery Issues
   • Cause: A weak or discharged battery is one of the most common reasons for poor starting in any engine, including the Mitsubishi L3E. Cold weather can exacerbate this problem by reducing the battery's ability to deliver sufficient power for cranking the engine.
     
   • Solution: Check the battery’s voltage with a multimeter. A fully charged battery should have around 12.6 volts when the engine is off. If the voltage is low, charge or replace the battery as needed. Also, check the battery terminals for corrosion or loose connections, which can further hinder proper starting.
     
2. Fuel System Issues
   • Cause: Problems with the fuel system, such as clogged fuel filters, air in the fuel lines, or a malfunctioning fuel pump, can result in poor fuel delivery to the engine, causing it to start sluggishly or fail to start altogether.
     
   • Solution: Inspect the fuel filter for clogs and replace it if necessary. Check for air bubbles in the fuel lines, which could indicate a leak or air intake. Ensure that the fuel pump is operating properly, and replace it if it is found to be faulty.
     
3. Glow Plug Malfunction
   • Cause: The Mitsubishi L3E engine relies on glow plugs to heat the combustion chamber for easier starting in colder conditions. If one or more glow plugs are faulty, it can make starting the engine difficult, particularly in low temperatures.
     
   • Solution: Test the glow plugs for proper functionality using a multimeter. If any of the glow plugs are not working, replace them with new ones to ensure optimal starting performance.
     
4. Starter Motor Problems
   • Cause: The starter motor is responsible for turning the engine over during startup. If the starter motor is worn or malfunctioning, it can cause slow or unsuccessful starts. Common symptoms include a clicking noise or no response at all when attempting to start the engine.
     
   • Solution: Check the starter motor for signs of wear, such as excessive noise or poor engagement. Inspect the wiring and connections leading to the starter motor. If the starter motor is faulty, it will need to be replaced or repaired.
     
5. Incorrect or Low-Quality Fuel
   • Cause: Using the wrong type of fuel or low-quality fuel can cause poor starting and engine performance. Diesel engines, such as the Mitsubishi L3E, require clean, high-quality fuel for efficient operation. Contaminated fuel can cause starting issues or even damage the engine over time.
     
   • Solution: Ensure that you are using the correct type of diesel fuel for the engine. If fuel contamination is suspected, drain the fuel tank and replace it with fresh, high-quality diesel. Clean or replace any fuel filters that may be clogged with debris.
     
6. Compression Problems
   • Cause: Low compression in the engine cylinders can make it difficult for the engine to start. This can result from worn piston rings, cylinder head gasket failure, or other internal engine issues that prevent proper compression.
     
   • Solution: Perform a compression test to determine if the engine is experiencing low compression. If the compression is low, it may be necessary to inspect and repair or replace the piston rings, cylinder head gasket, or other internal engine components.
     
7. Cold Weather Issues
   • Cause: Cold temperatures can have a significant impact on the engine’s ability to start, especially if the engine has not been properly winterized. Cold weather thickens the oil and fuel, making it harder for the engine to turn over.
     
   • Solution: Use winter-grade diesel fuel and ensure that the engine oil is suitable for low temperatures. Consider adding a block heater or using an engine pre-heater to help warm the engine and its components before starting.
     

Troubleshooting Steps

1. Check the Battery
   • Inspect the battery’s voltage and condition. Charge or replace the battery if necessary and clean the terminals to ensure good electrical connections.
     
2. Inspect the Fuel System
   • Check the fuel filter for clogs and replace it if necessary. Inspect the fuel lines for leaks and ensure the fuel pump is functioning properly.
     
3. Test the Glow Plugs
   • Use a multimeter to test the glow plugs. Replace any faulty glow plugs to ensure proper preheating for cold starts.
     
4. Examine the Starter Motor
   • Listen for any abnormal sounds from the starter motor. Inspect the wiring and replace the starter motor if it is malfunctioning.
     
5. Use the Correct Fuel
   • Verify that the fuel used is appropriate for the engine and is free from contaminants. If needed, drain the fuel tank and refill it with fresh, clean diesel fuel.
     
6. Test Engine Compression
   • Perform a compression test to ensure the engine has sufficient compression. Repair any internal engine issues that are causing low compression.
     
7. Prepare for Cold Weather
   • If operating in cold conditions, ensure that the engine is winterized. Use winter-grade fuel and ensure the oil is appropriate for low temperatures. Consider using engine heaters to assist with starting.
     

Conclusion
Poor starting issues in the Terex TC16 with the Mitsubishi L3E engine can stem from various causes, including battery problems, fuel system issues, faulty glow plugs, and cold weather conditions. By performing a thorough inspection of the fuel system, electrical components, and engine internals, operators can diagnose and fix the problem. Regular maintenance and proper winterization can help prevent these issues, ensuring that the Terex TC16 performs reliably in all conditions.