In hot weather, there is more stress on the parts of a fuel pump than under normal conditions, which therefore makes it more prone to failure. Fuel pumps operate with high pressure, transferring fuel between 40 and 70 psi, cooled and lubricated by fuel itself. With increased ambient temperature, the fuel in the tank becomes less dense, and because of this, the pump faces difficulty in maintaining proper fuel flow and pressure. Overheating results, with rapid wear on the motor and seals of the pump.
In hot environments, especially during the summer months, the inside of a vehicle can reach over 100°F (37.8°C), especially in the engine compartment where the fuel pump is located. In fact, according to AAA’s 2022 report on fuel pump failures, more than 30% of fuel pump failures in hotter climates were due to extreme heat exposure that led to the breakdown of critical pump components such as the armature, bearings, and seals. After lengthy exposure to high temperatures, the rubber seals deteriorate to affect both fuel leakage and internal friction furthering pump failure.
“The heat in modern vehicles is brutal on fuel systems, said James Scott, automotive technician. Many pumps begin to fail after extended use at high temperatures, and that starts occurring around 100,000 miles, though this figure may go down for extremely hot conditions.” Where summer temperatures always seem to stay above 90°F (32°C), a fuel pump’s normal expected life-8 to 10 years or 100,000 miles-may be significantly reduced. Under such conditions, fuel pumps start to fail much earlier than this.
High temperatures also affect the electrical components of the pump. When the fuel pump’s electrical circuit overheats, it may cause the failure of the relay or wiring connections. This results in intermittent power supply to the pump and causes it to operate erratically or stop functioning altogether. For example, the Bosch Automotive study from 2019 shows that in very hot areas, 15% of electrical fuel pump failure was due to overheat of the electrical head. In some instances, faulty wiring and burned-out fuses added to the cause of the failure.
Another problem is related to fuel vaporization. Fuel can even vaporize inside the fuel lines in extremely hot conditions, creating air pockets that disrupt the flow and cause the engine to stall or misfire. In addition, fuel pumps are only designed to move liquid fuel, so when there is vaporized fuel present, it puts extra load on the system and makes the pump work harder, which eventually increases the chances of damage. Most vehicles operating in hotter climates have vapor return lines for just this purpose, but these can also be stressed to the breaking point in exceptionally hot temperatures.
For these situations involving high temperatures, many complaints can arise among drivers, which might be directly related to symptoms like rough idling, hesitation, or stalling, while pointing at the failing fuel pump. For instance, a study conducted in 2021 by Consumer Reports stated that 20% of vehicles experiencing hot weather-related fuel system failures have an overheated pump or a problem with vapor lock.
To avoid fuel pump failure from high temperatures, one should regularly maintain their automobiles. The risk can be reduced by replacing fuel filters and checking fuel lines for any leaks or cracks. Keeping the fuel level at a sufficient mark will ensure that the fuel pump is always lubricated and cooled. For high-quality, durable fuel pumps that can bear extreme temperatures, visit Fuel Pump for reliable replacements meeting industry standards to help extend the life of your vehicle’s fuel system.