The 5 Main Ways Fuel Pumps Fail

Broken pump

Fuel pumps fail for many reasons, but the most common are:

  1. Lack of lubrication
  2. Overwork
  3. Burned connectors
  4. Corrosion
  5. Dirty fuel

Of course, each of these reasons for failure are often related...a lack of lubrication leads to an overworked fuel pump, corrosion can lead to dirty fuel, etc. But by understanding the five main causes of failure, we can maximize the lifespan of currently functioning fuel pumps, as well as diagnose problems.

Lack of Lubrication

Gassing upOne way to keep your fuel pump running smoothly? Keep the tank topped off.

An electric fuel pump - which is standard equipment in most cars made after 1990 - is an "immersion" pump. This means the pump is submerged in the fuel that's inside your vehicle's fuel pump. This is a good thing, as the gasoline around your fuel pump is both a coolant and a lubricant.

If your fuel tank spends more time hovering around "E" than it does "F", your fuel pump may not be properly lubricated. Most fuel pumps aren't properly lubricated once the fuel level drops below a quarter of a tank. If your fuel tank levels are always low, your fuel pump may fail due to a lack of lubrication.


An overworked fuel pump is one that has burned out (or is likely to do so soon). While there are safeguards that help keep a fuel pump from becoming overworked, these safeguards aren't perfect. For example, a fully submerged fuel pump operates at a lower temperature. But if the tank level is too low, the pump isn't being cooled.

Fuel pumps can also become overworked if they're improperly lubricated. Fuel pumps are lubricated by the gas in the fuel tank, so if the tank levels fall too low, the pump can become overworked. Contaminated fuel can also lead to an overworked fuel pump, as the contaminants can clog the fuel filter, making the fuel pump work harder.

Burned Connectors

Burned connectors occur because an overworked fuel pump overheats, drawing excessive electrical current for long periods. A high electrical load eventually leads to damaged or "burned" connectors in the fuel pump’s harness. Eventually, these connectors become so damaged that they can't provide enough electrical current, which leads to low fuel system pressure. Low pressure can cause slow acceleration, stalling, etc.


CorrosionFor the record, this is what a corroded fuel pump looks like.

Low fuel levels or fuel that has water in it can lead to corrosion of the fuel pump connectors. A pump that is exposed to air (not immersed) for long periods or that has been subjected to water will eventually corrode and become faulty or inoperable. Corrosion can also lead to burned connectors.

Dirty/Contaminated Fuel

Although not a common cause of fuel pump failures, dirty fuel can cause or aggravate the other problems on this list. Contaminated fuel can contribute to corrosion, as contaminants can cause or accelerate corrosion. Contaminated fuel can lead to overwork, as contaminants can clog fuel filters and pump inlet screens. Contaminated fuel can lead to lubrication problems as well.

How To Keep Your Fuel Pump From Failing

To summarize, many causes of fuel pump failure are preventable. Some things that vehicles owners can do to keep their fuel pump from failing:

  1. Keep the fuel tank at least one quarter full at all times. That ensures the fuel pump stays cool and lubricated.
  2. Avoid contaminated fuel by always buying gas from the same gas station. That way, if you start to have problems with clogged fuel filters, you know you need to buy gas from another station.
  3. Should you need to replace your fuel pump, be sure to inspect all connectors carefully, check the condition of the fuel filter, and follow installation instructions closely.

Finally, be sure to buy an OEM quality fuel pump if you need a replacement. Auteria is a global producer of fuel pumps, providing our pumps to numerous well-known after-market fuel pump brands as well as OEMs.