Troubleshooting Smoke and Spark Issues in Bobcat 873 Turbo

[MikePhua]

Bobcat's 873 Turbo skid steer loader is a popular machine used for a variety of tasks, ranging from construction to landscaping. However, like any heavy equipment, the 873 Turbo can face its own set of challenges. One common issue that can arise is excessive smoke and spark-throwing during operation. This article will explore the possible causes of these issues, provide diagnostic steps, and suggest solutions to get the machine back to optimal performance.
Understanding the Bobcat 873 Turbo Skid Steer
The Bobcat 873 Turbo is part of the Bobcat skid steer family, which has been known for its versatile and durable machinery. The 873 Turbo was specifically designed with a turbocharged engine to offer enhanced power, capable of lifting heavy loads and maneuvering in tough conditions. A key feature of the 873 Turbo is its 2,400-pound rated operating capacity, and the unit is powered by a 58-horsepower diesel engine. When the machine is running correctly, it’s known for its reliability and performance, but when it experiences issues like smoking or throwing sparks, it can quickly become a significant hindrance on a job site.
Common Causes of Excessive Smoke in Bobcat 873 Turbo

1. Dirty Air Filters
   Air filters are critical in maintaining the proper air-to-fuel ratio in the engine. A clogged or dirty air filter can restrict airflow, leading to an improper fuel burn. This can cause the engine to run rich, producing excessive black smoke from the exhaust. If the air filter is dirty, it is important to replace or clean it thoroughly before running the machine again.
   
2. Fuel Issues
   Fuel quality plays a pivotal role in the smooth operation of diesel engines. Low-quality or contaminated fuel can result in incomplete combustion, which can produce white or blue smoke. The presence of water or dirt in the fuel system can further complicate the problem, leading to engine misfires and the potential for spark-throwing from the exhaust system.
   
3. Overfilled or Contaminated Oil
   Overfilled oil in the engine can cause smoke, as the excess oil is burned during operation. Similarly, using the wrong type of oil or mixing oils with different viscosities can create operational issues. Always ensure the oil is at the correct level and type as specified by the manufacturer.
   
4. Worn Turbocharger Components
   Since the Bobcat 873 Turbo is equipped with a turbocharged engine, any issues with the turbo components, such as the seals or the shaft, can result in oil leaking into the intake or exhaust system. This oil burn will produce blue or gray smoke. Regular inspection of the turbocharger for wear and tear is essential for diagnosing turbo-related issues.
   
5. Injector Problems
   The fuel injectors are responsible for delivering a precise amount of fuel to the engine. If these injectors become clogged, damaged, or misaligned, they may lead to improper fuel delivery. This can cause smoke as well as engine sputtering or misfires. It’s important to have the injectors inspected if you suspect they may be the cause of the issue.
   

Spark Throwing Issues in Bobcat 873 Turbo
While spark-throwing is less common than smoke-related issues, it can still occur in machines like the Bobcat 873 Turbo. Spark-throwing is often a result of faulty components in the ignition system or exhaust system.

1. Exhaust System Problems
   A damaged or improperly installed exhaust system can cause sparks to be expelled through the exhaust pipe. The most common causes of exhaust-related spark-throwing include rusted or cracked pipes, loose connections, or broken catalytic converters. A thorough inspection of the exhaust system can often identify these issues.
   
2. Ignition System Failure
   An improper spark from the ignition system can also lead to spark-throwing from the engine. This may be caused by worn spark plugs, faulty ignition coils, or a malfunctioning electronic control unit (ECU). If the ignition system is to blame, replacing damaged components and resetting the ECU may solve the issue.
   

Diagnostic Steps
To accurately diagnose the source of smoke and spark issues, follow these steps:

1. Visual Inspection
   Begin with a thorough visual inspection of the Bobcat 873 Turbo. Check for any visible signs of oil or fuel leaks, smoke, and spark emission points. Inspect the air filter, exhaust system, and fuel lines to ensure no obstructions or damage exist.
   
2. Check Oil and Fuel Levels
   Confirm that both the oil and fuel levels are correct. Ensure that no contaminants are present in the fuel system and that the oil is of the correct type and quantity.
   
3. Test the Turbocharger
   Inspect the turbocharger for signs of wear or oil leaks. A damaged turbocharger should be replaced immediately to prevent further damage to the engine.
   
4. Check the Fuel Injectors
   If the issue persists, the next step is to test the fuel injectors for blockages or misalignment. A malfunctioning injector should be cleaned or replaced.
   
5. Examine the Ignition System
   For spark-throwing, test the ignition system components, including the spark plugs, coils, and ECU. Faulty parts should be replaced as needed.
   

Solutions and Recommendations

1. Replace the Air Filter
   A dirty air filter is an easy fix and should be replaced or cleaned regularly as part of the machine's routine maintenance.
   
2. Use High-Quality Fuel
   Always use high-quality fuel and ensure the fuel system is free of contaminants. It may be necessary to install a fuel filter or water separator to prevent future issues.
   
3. Turbocharger Inspection
   If the turbocharger is the problem, it may be worth replacing it altogether, especially if the seals or shaft are damaged. Regular maintenance checks on the turbo can prevent major failures down the line.
   
4. Fixing the Exhaust System
   Repair or replace any damaged components in the exhaust system, including pipes, gaskets, and catalytic converters. Regular cleaning of the exhaust system can help maintain performance.
   
5. Ignition System Maintenance
   Maintain the ignition system by regularly inspecting and replacing spark plugs, ignition coils, and any damaged wiring. If the ECU is malfunctioning, it may need to be reset or replaced.
   

Conclusion
Smoke and spark-throwing issues in the Bobcat 873 Turbo can be a headache for operators, but with the right approach, these problems can be effectively addressed. Regular maintenance and timely troubleshooting are key to preventing these issues from escalating. By following a thorough diagnostic process and replacing worn or faulty components, operators can restore the Bobcat 873 Turbo to its full operational capacity. Proper care and attention to detail will not only extend the lifespan of the machine but also ensure it continues to perform reliably on the job site.