Gasoline that is mistakenly poured into a diesel engine can potentially damage the diesel engine pump, fuel tank, fuel lines, injectors and other engine plumbing. The damage to the system will likely entail large repair costs with some of the key components of the engine needing to be replaced. When accidentally filled with gasoline, a diesel-engine car will still be able run for about a minute or so before stalling.
Although some diesel engines can run on gasoline for a short distance without suffering any significant damage, experts' advice is to stop the engine immediately once the mistake has been discovered. There are several probable reasons "misfueling" happens. These may include unfamiliarity with a borrowed or loaned vehicle or just a simple lapse in concentration.
Diesel engines have a specific requirement for fuel viscosity, and it is vital to keep the moving parts of the diesel engine pumps adequately lubricated. Since gasoline is less viscous than diesel fuel, it cannot provide the proper lubrication to the engine.
When a diesel engine is misfueled with gasoline, the engine should not be restarted and the car owner should call a garage for assistance. The solution to this problem is simple, but it is by no means cheap. The gasoline must first be drained from the tank and the parts that were contaminated with gasoline will have to be rinsed with diesel. If the damage is substantial, several key engine parts will have to be replaced, leading to higher repair costs.