5 Common Issues Solved with Roadside Diesel Repair

Dec 29th 2024

Top 5 Common Issues Causing Semi-Truck Breakdowns

Semi-trucks are the backbone of the transportation industry, but breakdowns can bring your operation to a halt. Understanding the most common issues that lead to breakdowns—and how to address them—can save you time and money. From DEF aftertreatment problems to electrical gremlins, here are the top 5 issues and solutions to keep your rig on the road.

1. DEF and Emissions Aftertreatment Issues

Common Causes:

Low DEF quality
NOx sensor malfunctions
DEF doser issues
SCR system inefficiencies

How to Fix It:

Test DEF Quality: Ensure your DEF meets the proper 32.5% concentration. Contaminants like diesel fuel or additives can compromise quality, so always source DEF from reputable suppliers.
Diagnose NOx Sensors: Faulty NOx sensors can send incorrect readings, leading to derates. Replacing them restores proper emissions regulation.
Repair DEF Doser: A malfunctioning doser may not spray enough DEF into the exhaust, causing high NOx levels. Check for voltage or circuit faults.
Inspect SCR System: If NOx conversion efficiency remains low despite other repairs, the SCR may need servicing or replacement.

Most DEF issues stem from hard part failures or wiring problems, not control module malfunctions. Prompt repairs prevent prolonged downtime and emissions violations.

2. Turbo, Actuator, and Air Handling Issues

Common Causes:

Turbo or actuator failure
Plugged air filters
Blown intercooler or damaged pipes
Faulty intake throttle valve

How to Fix It:

Replace Turbo or Actuator: If your truck has low power, no throttle response, or emits black smoke, the turbo or actuator may be failing.
Maintain Air Filters: Regularly replace air filters to prevent clogging, ideally every other oil change.
Repair Intercooler Components: Address holes in the intercooler or damaged pipes and boots to maintain proper airflow.
Inspect Throttle Valves: Ensure the intake throttle valve isn’t stuck, as this can restrict airflow and cause the engine to choke itself out.

3. Tire Issues

Common Causes:

Tire blowouts
Foreign objects causing punctures
Tires rubbing against broken trailer components

How to Fix It:

Monitor Tire Quality: Use high-quality tires and ensure proper inflation to prevent overheating.
Conduct Pre-Trip Inspections: Check for foreign objects, uneven wear, or alignment issues.
Replace Damaged Tires Promptly: Address tire failures immediately to avoid further damage or accidents.

4. Engine Problems

Common Causes:

Faulty sensors or injectors
Water pump or radiator leaks
Worn serpentine belts or tensioners

How to Fix It:

Replace Sensors and Injectors: Common failures include exhaust pressure sensors on Cummins ISX engines or injector issues on Paccar models.
Address Leaks: Check for external leaks from water pumps or radiators. Sometimes repeated failures stem from rubbing or improper installation.
Inspect Belts and Tensioners: Replace worn parts promptly, especially on models with known issues like Detroit DD15 engines.

Proactive maintenance can prevent many of these problems from escalating.

5. Electrical Issues

Common Causes:

Corrosion on battery terminals or connections
Wires rubbing or chafing
Shorts to ground or power
Burnt wiring from exhaust heat

How to Fix It:

Repair or Replace Wiring Harnesses: Severe damage may require a full replacement, while minor issues can often be resolved with an overlay harness.
Seal Connections: Prevent water intrusion and corrosion by properly sealing wiring connections.
Inspect Battery Connections: Ensure all cables and terminals are clean and secure to avoid power issues.

Electrical issues can be time-consuming to diagnose but addressing them thoroughly ensures long-term reliability.

Conclusion

Breakdowns are inevitable, but timely maintenance and repair can minimize their impact. If you're dealing with any of these issues, our expert team is here to help. At Diesel Truck Repair LLC, we specialize in diesel engine repair for construction equipment, trucks, and trailers.

We offer 24/7 mobile service