A petrol car that runs badly after refuelling is not automatically contaminated with water. Keep the fuel history, receipt and any other evidence. Describe the events and symptoms so the response considers water contamination alongside other possible faults.
Known water entry or a suspected fuel fault?
If water was accidentally poured into the petrol tank, state that directly and give the approximate amount. If contamination is only suspected, explain what makes you think it is water: the source used, a container incident, damage or symptoms after filling.
Poor running, hesitation or a non-start can have other explanations. A website cannot identify the contaminant from those signs alone. Do not add another chemical or repeatedly start the engine to test a theory while you arrange an assessment.
Information that helps the assessment
Provide the registration, approximate fuel level before filling and amount added. Include when the vehicle last ran normally, the source of the petrol and whether any other vehicle filled from the same container or supply.
If the engine has run, note the distance and sequence of symptoms rather than assuming a particular part is damaged. Explain any attempts to add fuel or treatments since the issue began. An accurate history helps the technician decide which work is appropriate.
Removal does not replace diagnosis
The appropriate response can involve removal of contaminated contents, cleaning and further checks. The vehicle’s tank and fuel-system arrangement affect what can be done at the location. A petrol system should not be treated as though it has the same water-separator maintenance process as a diesel vehicle.
If another fault or component damage is suspected, further diagnosis may be required. Removing one tankful does not prove the filler, cap, source or another possible route of ingress has been resolved. Those questions need attention before the same problem is repeated.
Arranging mobile assistance
Give the exact vehicle location and safe access details. At a filling station, inform staff; at home or a commercial site, explain parking, permission and any restrictions. Remote and island visits need their own attendance discussion.
The cost depends on the assessment, quantity, access and work. If the petrol came from a storage container or a larger tank, describe the source separately. Bulk storage work and laboratory testing should not be assumed to be included in a mobile vehicle drain.
Attendance, access and the cost of the work
Contamination enquiries are assessed for the vehicle, fluid, quantity, access and whether the engine has run. AdBlue, water and unknown-fluid work should not be assumed to have the same scope or price as a simple petrol-and-diesel mix.
We cover mainland Scotland and the islands. Arrival estimates are confirmed for the vehicle’s actual location and current availability. Time on site is a separate matter and depends on the work. Neither a coverage page nor an initial enquiry is a promise of a fixed completion time.
Before attendance, identify the person authorised to approve the work. The technician explains the proposed service and confirms the cost before starting. If you intend to use a policy, lease agreement or hire-company process, check its requirements with the provider.
Find your coverage areaWater in petrol: common questions
Can I tell that petrol contains water just by looking at it?
Do not rely on appearance alone or handle fuel to carry out an improvised test. Explain the incident and retain information about the source; further assessment may be needed.
Should I top the tank up with fresh petrol?
Adding more fuel does not establish that the existing contents are suitable. Arrange advice for the known or suspected contamination before adding another product.
Is water in petrol the same as diesel in petrol?
No. They are different contaminants. Tell us which is known or suspected, and explain the evidence so the appropriate response can be arranged.
Can a drain guarantee the warning light clears?
No. A warning may relate to another fault or require further checks. The vehicle needs assessment rather than a promise based on the tank contents alone.