Urgency: Moderate
Water in Fuel Light (Diesel)
Investigate soon. Driving short distances is generally okay, but book a diagnostic check.
What the Water in Fuel Light (Diesel) Means
The water-in-fuel light on a diesel your car warns that water has collected in the fuel filter/separator. Water is very damaging to a diesel injection system, so drain it promptly.
Common Causes
- Water accumulated in the fuel separator
- Condensation in a low fuel tank
- Contaminated or poor-quality diesel
- Faulty water sensor
- Fuel filter overdue for service
How to Fix It
- Drain the water from the fuel filter/separator (per the manual)
- Avoid running the tank very low to reduce condensation
- Use reputable fuel stations
- Replace the fuel filter if overdue
- Check the water sensor if the light stays on after draining