How Do Sensors Get Dirty or Damaged?

Car oxygen sensor

Sensors play an integral role in the performance of your car’s engine. When one sensor stops working, it can cause the entire system to malfunction. The diagnostic computer relies on the information provided by the sensors to ensure the system is working correctly. While many things can happen to cause problems with one or more sensors, one of the biggest issues is them simply getting dirty.

These primary sensors relay information to the diagnostic computer so that it can make adjustments on how the systems function. The oxygen sensor, manifold absolute pressure sensor, and mass airflow sensor monitor the amount of air in the system to ensure an accurate fuel/air mixture in the engine.

Wheel speed sensors let the ABS system know if one wheel has lost traction. This enables the system to readjust and keep your car in control and on the road.

How sensors get dirty

Oxygen sensors get contaminated by chemicals that leak into the exhaust. For example, silicates enter the area when the coolant leaks because of a crack in the cylinder wall or a leaking head gasket. Phosphorus gets in the exhaust from oil leaks because of worn rings.

Mass airflow sensors, or MAF sensors, become dirty from fuel varnish. Dirt will attach to the heating element and cause it to report incorrectly how much airflow is occurring.

Wheel speed sensors are often damaged rather than accumulating dirt, but they may attract iron particles which will limit their functionality. If they are damaged, it’s generally the wiring rather than the actual sensor.

The manifold absolute pressure sensor is located near the intake manifold and will get debris and dust on it. Cleaning the MAP sensor will restore it back to working order.

How sensors get damaged

When other components aren’t working correctly, they can cause damage to the sensors. For instance, the coolant sensor may be damaged if the engine overheats. The throttle position sensor becomes worn over time with regular use.

Sensors that read tire pressure generally stop working when the batteries die. The sensor will need to be replaced rather than just the batteries. Sometimes, tire sealant products can cause the sensor to become dirty.

If you suspect that a sensor isn’t working properly, try to clean it before you replace it. Taking a few minutes to clean your sensor could save you a lot of money. Replacing it may be the next step if the sensor is damaged. A faulty sensor can cause major damage to your vehicle or reduce performance if you continue driving.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Car trouble?

Our mechanics make house calls.

  • Get a quote & book a service online
  • Save up to 30% compared to shops
  • Repairs, maintenance & diagnostics
  • 12-month, 12,000-mile warranty
GET A QUOTE

Excellent rating

Rating@3x

Need a mechanic?

Our certified mobile mechanics make house calls in over 700 U.S. cities. Fast, free online quotes for your car repair.

Get a quote

Post a question and get free advice from our certified mechanics.


Ask a question