* Internal Tank Corrosion: This is the most likely culprit. Over time, especially in areas with harsh weather conditions (salt, humidity), the inside of the fuel tank can corrode. This corrosion can flake off, contaminating the fuel. Diesel fuel itself can contribute to corrosion in certain circumstances. The type of steel used in the tank and the quality of its protective coating are factors here.
* Fuel Quality Issues: Using low-quality fuel containing excessive amounts of water, contaminants, or biofuel degradation products can accelerate corrosion and flaking. Poor fuel filtration can also exacerbate the problem.
* Tank Liner Degradation: Some fuel tanks have a protective liner. If this liner fails or degrades, it can lead to the base metal corroding and flaking.
* Manufacturing Defect: Although less common, a manufacturing defect in the tank's construction or coating could predispose it to early flaking.
What to do if you suspect flaking:
1. Immediate Action: Do *not* continue to drive the vehicle. Driving with flaking material in the fuel system will severely damage the engine's fuel injectors, fuel pump, and other sensitive components.
2. Inspection: Have a qualified mechanic inspect the fuel tank. This will likely involve draining the tank and visually inspecting the interior for flaking. A borescope may be used for better access.
3. Fuel Sample Analysis: A fuel sample should be taken and analyzed to determine the extent of contamination.
4. Repair or Replacement: Depending on the severity of the flaking, the fuel tank may need to be repaired (if repairable) or replaced. A thorough cleaning of the entire fuel system will also be necessary to remove any loose particles.
5. Cause Investigation: Determine the root cause. If it's due to poor fuel quality, change your fueling habits. If corrosion is the problem, consider the environmental factors and the vehicle's age.
Important Considerations:
* Warranty: Check if your vehicle is still under warranty. This type of failure might be covered.
* Cost: Replacing a fuel tank can be expensive, as can the extensive cleaning and repair of the fuel system.
* Safety: Fuel tank issues are potentially dangerous. Handle the situation with caution.
If you're experiencing this issue, it's crucial to seek professional help immediately from a qualified diesel mechanic experienced with heavy-duty trucks. Do not attempt to diagnose or repair this yourself. The consequences can be severe.
