Keeping your diesel fuel tank clean is one of the most important maintenance tasks for preventing engine problems and ensuring peak performance. Over time, moisture, contaminants, and sludge can build up inside the tank, clogging fuel lines and filters. This restricts fuel flow to the engine, potentially causing sputtering, loss of power, and even engine failure. By learning how to properly clean your diesel fuel tank, you can restore full fuel flow and avoid costly repairs down the road.
Why Cleaning Your Diesel Fuel Tank is Important
Diesel fuel can begin to degrade shortly after production. Factors like heat, air exposure, microbial growth, and impurities introduced during transport or storage can alter the fuel’s chemical composition. As the diesel breaks down, darker sediments and stickier residues start to form. These byproducts will eventually fall out of suspension and accumulate along the bottom and sides of your fuel tank.
Significant fuel degradation can start in as little as 6 months. Letting these contaminants build up over several years can lead to major engine performance and reliability issues. That’s why periodic fuel tank cleaning should be part of your regular maintenance routine.
Here are some of the biggest reasons to keep your diesel fuel tank clean:
- Restores full fuel flow to the engine
- Removes water and microbial growth
- Reduces risk of filter plugging
- Lowers chances of fuel line/injector fouling
- Improves fuel economy and power output
- Extends overall engine life
By taking preventative steps to remove contaminants and sediment from the fuel supply, you can avoid compromised performance and expensive repairs.
How Often to Clean Your Diesel Fuel Tank
Most experts recommend inspecting your diesel fuel tanks at least once annually and cleaning them every 2-3 years. However, the optimal service interval can vary considerably based on these factors:
- Fuel Quality – If you regularly use high-quality diesel with fuel stabilizers added, you may be able to go longer between cleanings. Lower quality fuels degrade faster.
- Tank Size – Larger tanks over 100 gallons are more prone to significant water and debris accumulation. Smaller tanks need less frequent cleaning.
- Mileage – The more you drive, the faster moisture and sediments will build up. Infrequently used diesel vehicles need less frequent tank cleaning.
- Climate – Warm humid conditions accelerate fuel degradation. Cooler drier climates are less problematic.
- Maintenance History – If your tanks have never been cleaned, the first cleaning may reveal extensive contaminant buildup. Future cleanings won’t need to be as frequent.
Pay attention for signs of reduced performance or changes in your engine’s behavior. When in doubt, it’s better to clean your diesel tanks more often than necessary rather than allowing excessive degradation and sludge buildup.
Signs Your Diesel Fuel Tank Needs Cleaning
Don’t wait until serious engine problems arise. Watch for these common warning signs that indicate it’s time to clean your diesel fuel tanks:
- Difficulty starting the engine
- Sputtering, loss of power under load
- Black smoke from exhaust
- Foul fuel odor
- Knocking or pinging sounds
- Higher than normal fuel consumption
- Fuel filter plugging ahead of schedule
Any of these symptoms can signal restricted fuel flow from contaminant buildup in the tank and fuel system. It’s important to address them promptly before permanent damage occurs.
When contamination levels get extreme, you may even see reduced fuel tank capacity as sludge and sediment displace usable fuel volume. The debris can also detach from the tank interior and plug fuel lines, filters, and injectors.
Cleaning the tank immediately helps remove the contaminants causing these issues and prevent escalating problems down the road.
What You’ll Need to Clean a Diesel Fuel Tank
Diesel fuel tank cleaning can be challenging DIY project. Having the right gear makes the process considerably easier and safer:
Fuel transfer pump – Used to remove most of the diesel from the tank before cleaning. This helps reduce environmental hazards from fuel spills.
Siphon pump – To drain out as much leftover fuel/contaminants as possible once the main fuel supply is extracted.
Fuel tank entry tool – Provides an access point to insert cleaning equipment into the tank.
Wash wand – Connects to a pressure washer to spray inside the tank and dislodge contaminants.
Tank cleaning fluid – Specially formulated products help break down deposits and carry them out of the fuel system.
Scrub brushes – For manual scrubbing of tough debris inside the tank.
Fuel filter wrench – For safe filter removal/replacement to prevent loose sediment from re-entering the fuel lines.
Containment mats – Capture any spilled fuel or chemicals when working under the tank.
Gloves, goggles, coveralls – Protect yourself from fuel and chemical contact.
Cleaning tools – Small shovels, catch pans, and buckets come in handy for removing debris flushed from the tank.
With the right gear, you can thoroughly clean the inside of the tank, fuel pickup, lines, and filters to restore unrestricted fuel flow.
Step-by-Step Guide to Cleaning a Diesel Fuel Tank
Follow these key steps to safely and effectively clean your diesel fuel tank:
Step 1 – Drain the Tank
Use an external fuel transfer pump to drain all accessible liquid fuel from the tank and store it in approved fuel containers. Position the pump suction line through the fill port. Remove as much fuel as possible before starting the cleaning process.
Step 2 – Disconnect Electrical, Fuel Lines, Sending Unit
Before cleaning the interior, disconnect the battery to disable the fuel pump. Remove any fuel supply and return lines. Also detach the fuel level sending unit.
Step 3 – Access the Tank Interior
Remove the drain plug, if equipped. Or use a tank entry tool to cut an access panel in the tank shell. This provides entry points for cleaning wands, hoses, and inspection.
Step 4 – Apply Cleaning Fluid
Apply a diesel fuel tank cleaning solution through the fill port or access panel according to the product instructions. As it circulates, the cleaner will break down sediment and deposits inside the tank.
Step 5 – Remove Remaining Fuel/Residue
Use a siphon wand to extract the tank cleaning fluid along with any re-suspended contaminants. Remove as much liquid as possible from the tank interior before further cleaning.
Step 6 – Pressure Wash Tank Interior
Insert a tank wash wand through the access points and thoroughly pressure wash all interior tank surfaces. This will flush away stubborn deposits and push them toward the drain point.
Step 7 – Scrub Interior by Hand
Use a long handled scrub brush reaching into the tank to manually dislodge any remaining debris from tight spaces and corners. This helps fully remove contaminants from the entire tank.
Step 8 – Flush the Tank
After manual scrubbing, perform a final pressure wash of the interior to flush all released contaminants through the drain point. Extract as much liquid as possible.
Step 9 – Clean Other Components
With the tank empty, clean the fuel pickup, supply lines, vent lines, valves, sender, and any other components before reassembly. Replace the fuel filter.
Step 10 – Dispose of Contaminants
Properly dispose of all drained fluids, chemical cleaners, and debris removed from the tank in accordance with hazardous waste regulations.
Step 11 – Inspect Tank Interior
Perform a visual inspection of the interior through the access points. Ensure all rust, scale, and sediments have been completely removed.
Step 12 – Reassemble Tank
Reinstall or replace any access panels. Reconnect all fuel supply and return lines, electrical senders, valves, vents, etc. according to factory specifications.
Step 13 – Refill with Fresh Fuel
Add fresh high-quality diesel fuel to the tank. Prime the fuel system and start the engine to verify normal operation. Consider adding a diesel fuel supplement for further system cleaning.
With these steps, you can thoroughly clean contaminants from the tank interior and fuel system components. This will help maximize engine performance while reducing wear on pumps, injectors, and other parts.
Tips for Effective Diesel Fuel Tank Cleaning
Here are some useful tips to help tackle the cleaning process like a pro:
Use fuel stabilizer additives – High-quality diesel fuel stabilizers help deter sludge formation and degradation between cleanings. This keeps your tanks cleaner longer.
Clean in dry weather – Avoid humidity and precipitation. Moisture entering the tank can counteract cleaning.
Work in a ventilated area – Diesel fumes and cleaning chemicals mandate good ventilation.
Take safety precautions – Fuel and chemicals call for protective gear to avoid burns, inhalation, and skin contact.
Remove all accessible fuel – Drain as much fuel as possible before starting interior tank cleaning. This simplifies the job and reduces spill hazards.
Clean affected components – Don’t stop with just the tank. Clean fuel filters, lines, valves, pickup, vent, sender, etc.
Inspect for corrosion – Replace components like fuel senders if cleaning reveals significant corrosion or perforations.
Consider professional help – For extensive sludge removal or interior tank coating, pros have the tools and disposal capabilities.
Investing a little extra effort goes a long way toward getting your tank squeaky clean and keeping your diesel engine running reliably.
Professional Diesel Fuel Tank Cleaning Services
Extensive contaminant buildup or internal tank corrosion may exceed the capabilities of DIY cleaning methods. Professional fuel tank cleaning services use high-pressure hot water blasting and industrial vacuuming equipment to thoroughly scour the interior and remove all traces of debris.
They also have chemicals and techniques to address severe microbial growth. Additionally, they dispose of all hazardous waste properly.
Look for service companies that specialize in diesel fuel tank cleaning versus general automotive services. Ask about their specific cleaning process, equipment used, and any related services like fuel polishing or tank coating.
Expect to pay anywhere from $200 up to $2,000+ depending on the tank size, level of contamination, and cleaning methods required. This investment can pay off by resolving stubborn fuel system issues and preventing costly component replacements.
Keep Your Tank Clean Going Forward
While periodic deep cleaning is recommended, you can take steps to keep your diesel fuel tanks cleaner between service intervals:
Add biocides – Kill microbial growth within the tank that causes fuel degradation and sludge.
Use fuel stabilizers – Detergents and corrosion inhibitors help maintain fuel stability and cleanliness.
Fill up frequently – Don’t let tanks run low. Less fuel means more internal corrosion.
Block sunlight – Ultraviolet light accelerates fuel breakdown. Park indoors or use tank blankets.
Check for water – Regularly drain water separators to keep moisture out of the tank.
Replace fuel filters – Clogged filters signal issues so you can address the root cause.
Clean annually – Even if not yet required, an annual inspection and fuel polishing helps maximize longevity.
Implementing these fuel maintenance best practices will minimize contaminant buildup and preserve engine performance. Your efforts will be rewarded with extended diesel engine reliability and lower repair costs. Just be sure to clean your diesel tanks thoroughly at the first signs of trouble to prevent further issues down the line.
