The sludge in the fuel tank is a viscous, dark residue that appears mainly in vehicles fueled with gasoline. The problem occurs due to the oxidation of unstable compounds present in the fuel, forming insoluble polymers that settle on the bottom and walls of the tank.
This process is silent and progressive. X__NM0____
Experts point out that the phenomenon is more common in flex-fuel cars that run predominantly on ethanol, as the gasoline in the auxiliary or main tank remains idle for months.
What accelerates the formation of sludge
Gasoline oxidation occurs naturally in the presence of oxygen and heat. Alguns factors make the process much faster.
Low quality or adulterated fuel contains greater amounts of olefins and diolefins, highly reactive substances that oxidize easily. Ambientes hot weather and high humidity also contribute.
Keeping the tank low on fuel increases the volume of internal air, favoring contact with oxygen. The fuel pump temperature rises when the level is low, accelerating degradation.
Signs that the car presents when there is sludge
The first symptoms are often subtle. The engine may fail when accelerating or idle unevenly.
The fuel filter clogs more frequently, requiring changes sooner than normal. At an advanced stage, difficulties arise when starting cold or hot.
The fuel pump starts to work with different noise and may burn out due to excessive effort. Injetores clogged causes loss of power and a significant increase in consumption.
Does premium or premium gasoline prevent the problem?
Many drivers believe that gasoline with additives or podium prevents sludge. Essa idea is wrong.
Detergent additives act mainly to clean valves and injection nozzles, but do not prevent oxidation inside the tank. Premium gasoline has a higher octane rating, but the same tendency to form gums when stored for a long period.
The quality of the fuel at the pump and storage time are the decisive factors, regardless of the type sold.
Simple care that prevents sludge in the tank
Always refuel at trusted stations with high sales volume. Evite leave the tank with less than 1/4 of its capacity for prolonged periods.
In flex-fuel cars, run on gasoline at least once a month to renew the fuel in the tank. Não store gasoline in gallons for more than 30 days.
If the vehicle will be parked for weeks, top up the tank before storing it. Isso reduces space for oxygen and reduces moisture condensation.
When it is necessary to clean the system
Vehicles with more than 80,000 km or that have shown symptoms must have the tank and supply circuit professionally cleaned.
The procedure includes complete drainage, washing with a specific product and changing the filter and, in some cases, ultrasound on the injectors. The service costs between R$600 and R$1,800 depending on the region and model.
Carrying out preventive maintenance every 40,000 km on cars that run little on gasoline avoids spending more on changing pumps and injectors.
