Troubleshooting the Bobcat S185: A Guide to Resolving Starting Issues

[MikePhua]

The Bobcat S185 is a versatile and durable skid-steer loader used in a wide variety of construction, landscaping, and material handling tasks. However, like all machinery, it can occasionally experience issues. One of the most common problems is the inability to start the machine. This issue can stem from a variety of causes, ranging from electrical issues to fuel system problems. This guide will walk you through the steps to troubleshoot and resolve starting issues with the Bobcat S185.
Common Symptoms of Starting Issues
When the Bobcat S185 fails to start, the operator may notice various symptoms, such as:

• The engine cranks but does not start.
  
• The engine does not crank at all.
  
• Intermittent starting issues.
  
• Clicking sound when trying to start the engine.
  
• The engine starts and stalls shortly after.
  

Identifying the specific symptoms can help narrow down the cause of the problem.
1. Electrical System Failures
The electrical system is often the first place to check when a machine fails to start. Electrical issues are a common cause of starting problems and can involve the battery, starter motor, or alternator.

• Battery Issues:
  • Symptoms: The engine may fail to crank, or you may hear a clicking sound when attempting to start the machine.
    
  • Cause: The most common cause of starting issues in the Bobcat S185 is a dead or weak battery. Over time, the battery can lose its charge or become damaged, preventing the engine from starting.
    
  • Solution:
    
    1. Check the battery voltage: Use a multimeter to test the battery voltage. A fully charged battery should read around 12.6 volts or more.
       
    2. Inspect for corrosion: Clean the battery terminals and cables, ensuring there is no corrosion that could impede the flow of electricity.
       
    3. Test the battery under load: If the battery voltage is low, try jump-starting the machine or replacing the battery with a known good one.
       
    4. Replace the battery: If the battery is faulty or not holding a charge, it may need to be replaced.
       
• Starter Motor Issues:
  • Symptoms: If the battery is good but the engine still fails to crank, the starter motor may be the issue.
    
  • Cause: A faulty starter motor can prevent the engine from turning over. This can be due to wear and tear or electrical issues within the starter.
    
  • Solution:
    
    1. Check the starter connections: Ensure that the starter motor connections are clean and secure.
       
    2. Test the starter motor: Use a voltmeter to test the starter motor’s operation by checking the voltage at the starter solenoid. If no voltage is present, the starter motor may need to be replaced.
       
    3. Replace the starter motor: If the starter motor is faulty and cannot be repaired, replace it with a new or rebuilt unit.
       
• Fuses and Relays:
  • Symptoms: The machine does not respond to the ignition or starts intermittently.
    
  • Cause: A blown fuse or a faulty relay can prevent the electrical system from supplying power to the starter motor or other essential components.
    
  • Solution:
    
    1. Check the fuses: Inspect the fuse box for any blown fuses and replace them as necessary.
       
    2. Inspect relays: If a fuse is intact, check the relays responsible for starting the engine. Faulty relays can be replaced easily.
       

2. Fuel System Problems
Fuel system issues can also prevent the Bobcat S185 from starting. Common problems include fuel contamination, clogged fuel filters, or a malfunctioning fuel pump.

• Fuel Contamination:
  • Symptoms: The engine cranks but does not start or starts briefly and stalls.
    
  • Cause: Contaminated fuel, such as water in the fuel tank, can prevent proper combustion and lead to starting issues.
    
  • Solution:
    
    1. Drain the fuel tank: If you suspect fuel contamination, drain the fuel tank completely.
       
    2. Inspect the fuel filter: Check the fuel filter for any clogs or dirt. Replace the filter if necessary.
       
    3. Clean the fuel system: After draining the contaminated fuel, clean the fuel lines and replace the fuel filter before refilling the tank with fresh fuel.
       
• Clogged Fuel Filter:
  • Symptoms: The engine cranks but fails to start, or it may start and then stall.
    
  • Cause: A clogged fuel filter restricts fuel flow to the engine, making it impossible for the engine to get the fuel it needs to run.
    
  • Solution:
    
    1. Check the fuel filter: Inspect the fuel filter for any signs of clogging.
       
    2. Replace the fuel filter: If the fuel filter is clogged, replace it with a new one.
       
• Fuel Pump Issues:
  • Symptoms: The engine does not crank or starts intermittently.
    
  • Cause: A malfunctioning fuel pump can prevent fuel from reaching the engine.
    
  • Solution:
    
    1. Check for fuel pressure: Use a fuel pressure gauge to check the fuel pressure at the injector rail. If the fuel pressure is too low, the fuel pump may be faulty.
       
    2. Replace the fuel pump: If the fuel pump is not providing adequate pressure, it may need to be replaced.
       

3. Air System Issues
The air system plays a critical role in engine performance. If there is an issue with the air filter, intake system, or sensors, the engine may not start properly.

• Clogged Air Filter:
  • Symptoms: The engine cranks but does not start, or it starts and stalls after a few seconds.
    
  • Cause: A clogged air filter can restrict airflow to the engine, causing it to stall or fail to start.
    
  • Solution:
    
    1. Inspect the air filter: Remove the air filter and inspect it for dirt or debris.
       
    2. Replace the air filter: If the air filter is dirty, replace it with a new one to ensure proper airflow.
       
• Faulty Sensors or Wiring:
  • Symptoms: Intermittent starting issues or no response from the engine.
    
  • Cause: Faulty sensors, such as the crankshaft position sensor or fuel pressure sensor, can prevent the engine from starting.
    
  • Solution:
    
    1. Inspect sensors and wiring: Check the wiring and connectors for signs of wear or damage.
       
    2. Test the sensors: Use a multimeter to test the functionality of the sensors. Replace any faulty sensors.
       

4. Ignition System Problems
If the ignition system is not working correctly, the engine may fail to start. Issues with the ignition switch, ignition coil, or spark plugs could be the root cause.

• Ignition Switch Issues:
  • Symptoms: The engine fails to turn over when the key is turned.
    
  • Cause: A faulty ignition switch could prevent the electrical system from powering up.
    
  • Solution:
    
    1. Test the ignition switch: Use a multimeter to test the continuity of the ignition switch.
       
    2. Replace the ignition switch: If the switch is faulty, replace it with a new one.
       
• Faulty Spark Plugs:
  • Symptoms: The engine cranks but does not start.
    
  • Cause: Worn or damaged spark plugs can prevent proper ignition in the engine.
    
  • Solution:
    
    1. Inspect the spark plugs: Remove the spark plugs and inspect them for wear or damage.
       
    2. Replace the spark plugs: If the spark plugs are worn or damaged, replace them with new ones.
       

5. Starter Relay or Safety Switch Issues
The Bobcat S185 has several safety features that prevent it from starting if not properly engaged, such as the seat switch, parking brake, and hydraulic lockout.

• Symptoms: The engine fails to start despite a good battery and fuel supply.
  
• Cause: A faulty safety switch, such as the seat switch or parking brake switch, can prevent the engine from starting.
  
• Solution:
  
  1. Check the safety switches: Inspect the seat, brake, and hydraulic lockout switches for proper operation.
     
  2. Bypass the switches: Temporarily bypass the switches to verify if they are causing the issue. If the machine starts, replace the faulty switch.
     

Conclusion
Starting issues with the Bobcat S185 can be caused by a variety of factors, including electrical problems, fuel system failures, air system blockages, and ignition system issues. By following the troubleshooting steps outlined above, you can diagnose and resolve many of the common problems that prevent the machine from starting. Regular maintenance, including checking the battery, replacing filters, and inspecting the fuel system, can help prevent these issues and keep your Bobcat S185 running smoothly for years to come.