Water in Diesel – Causes, Symptoms, Solutions
The presence of water in diesel is one of the most common and costly fuel system problems. Corrosion, bacterial growth and filter clogging can cause serious damage in a short time. The DQTube in-tank filter continuously removes water and contaminants, protecting your vehicles and machines from downtime and expensive repairs.
Why does water get into diesel?
Water can enter the fuel from several sources. For fleet managers and machine owners, it’s important to understand that these factors are often independent of the operator:
- Condensation: when temperatures fluctuate, moisture in the tank’s air condenses.
- Contaminated fuel: water can enter during delivery or at the refuelling station.
- Bio-component (FAME): promotes emulsion formation and provides a breeding ground for bacteria.
What symptoms does water in diesel cause?
The problem usually appears gradually but can lead to severe damage:
- Hard starting, rough engine running
- Loss of power, increased fuel consumption
- Clogged filters, frequent servicing required
- Corrosion in the tank and fuel system
- Injector and high-pressure pump failure
A major failure can cost hundreds or even thousands of euros – plus the downtime causes additional losses.
How to check for water in diesel?
- Shut down the machine and wait a few minutes for the sediment to settle.
- Take a sample from the bottom of the tank into a transparent jar.
- Check if a separate water layer or cloudy emulsion is present.
- Pro method: use a water indicator or test strip.
If you find water, do not run the engine – prevent more serious damage.
DQTube – In-tank Solution
DQTube is placed inside the tank and continuously removes water and solid particles without affecting the fuel’s chemical composition. Thus it:
- Reduces the risk of failures
- Extends the life of the engine and fuel system
- Relieves factory-installed filters
- Minimises unexpected downtime and breakdowns
Learn more about the different sizes, and choose the one that fits your fleet!
Contact us nowFrequently Asked Questions
Why is water in diesel dangerous?
It causes corrosion, promotes bacterial growth, clogs filters, and may lead to serious engine damage.
What are the typical symptoms?
Hard starting, stuttering, power loss, error codes in the fuel system.
How can it be prevented?
With regular inspection, quality fuel, and by using a DQTube in-tank filter.
Does DQTube replace the factory fuel filter?
No. It complements it: works in the tank, reduces water and contaminants, and eases the load on the factory filter.