Published Oct 28, 2022

Water and diesel are a bad mix. While it’s common to find them together, excessive amounts of water will eventually cause major engine damage. There are three common sources of water in diesel tanks:

  1. Handling issues. Diesel is hygroscopic, meaning it holds onto large amounts of water. The result is that water is often found in diesel tanks – including the ones at your local service station. Because of this, it’s possible to introduce diesel into your own vehicle when refilling from contaminated storage tanks.
  2. Fuel tank leaks. Small leaks in the diesel tank, fuel filler cap or fuel filler neck can allow water to enter the tank. Simple washing or rain can contaminate the fuel and cause major problems for your engine.
  3. Condensation. Unlike petrol, diesel is a very stable fuel source that produces relatively low amounts of vapour. This creates a unique problem in diesel tanks. The lack of vapour means that tanks often contain large amounts of air. As the ambient temperature changes, the tank draws in humid air and moisture condensates on the inside of the tank walls. Eventually, this condensation process can result in large buildups of water in your diesel tanks..
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