Q: How Do Fuel Injectors Get Dirty?

asked by on

How do fuel injectors get dirty?

The gasoline we buy at our local gas station may look golden-clean but, in truth, by the time it reaches the fuel injector, it has come into contact with impurities that will over time coat critical areas of the injector.

The high temperatures in the body and especially at the tip of a modern fuel injector, can promote varnishing of internal components. The injectors are amazing engineering wonders that with the advent of Direct Fuel Injection (the latest fuel injection design that places the injector directly into the combustion chamber), now routinely handle fuel pressures of up to 2000 PSI and the increased temperatures of being situated directly in the combustion chamber.

These extremely high pressures, coupled with tiny internal passages that lead to 10 to 20 micron (1 micron is the size of the period at the end of this sentence) final filter screens, mean that even minor rust, oil, or other impurities will ultimately lead to a dirty fuel injector.

Symptoms of dirty fuel injectors include a lean misfire, rough idle, hesitation and stumbling on light acceleration, a loss of power, and higher hydrocarbon (HC) and carbon monoxide (CO) emissions.

There are numerous products on the market to add to the gas tank to clean injectors as we drive and external cleaning units that force detergent-infused products through the injectors to clean minor buildup. However, once an injector gets to the point of consistently producing the symptoms listed above, the only fix will be to replace the fuel injector.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. How Do Fuel Injectors Get Dirty?

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Car accelarates to 3000 rpm in park or neutral.

The throttle position sensor (TPS) is most likely failing. Air leaks in the intake can also generate a high idle, but not usually this high. If you need to have this checked, have a local mechanic, like one from YourMechanic,...

Q: Secondary air pump.

The air pump supplies the catalytic converter with extra oxygen so that it can efficiently catalyze any unburned fuel. On start up, the catalytic converter is cold and requires some help to quickly get up to temperature allowing it to...

Q: Engine misfiring and shut off

Engine misfires can be caused by many different problems, but there are a few suspects that occur more than others. Generally, misfires are caused by either a spark or fuel issue or in cases, a combination of both. Spark related...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...