Janesville Automotive Airflow Maintenance

Newer vehicles do not require as much maintenance as older ones do. The internal combustion engine is still an air pump though. If more air gets through the engine, more fuel can be burned and more horsepower will be generated. Below is an insight into a airflow maintenance and what happens during a tune-up.

Air Filters:

Air filters keep out dirt, but as the filter element fills up with particles, airflow is greatly decreased. The filter element is removed during a tune-up and is checked to see if it is dirty. There are a few ways to do this like holding it up to a shop lamp. If it is dirty, then it needs to be replaced.

MAF Sensor:

The MAF sensor is also known as the mass airflow sensor. It’s normally not dealt with, unless it is causing problems. Hairs from the filter can collect on the sensor wire though and that causes a lean stumble. The sensor is cleaned with aerosol products to keep it free of debris. The air intake ducting is removed and the product is sprayed onto the “hot wire”.

Throttle Bodies:

The throttle plate or plates collects debris and that leads to a gradual  choke off airflow when the car is idling. Due to the fact that the bottom of the throttle plate is exposed to oil and fuel films, the fumes are allowed to condense on the throttle plate. That in turn collects more debris. If the plate gets filthy enough the car may surge at low RPMs. TO clean the plate, it can be remove or it will be wired open. Then it is cleaned with a toothbrush and cleaning solution often.


Port injected engines often have lots of residue from fuel fumes and the stem side of an intake valve develops “cauliflower” easily. These carbon-like deposits cause it to run lean when it is soaking up fuel and then runs rich when it gives up fuel, which affects the amount of air flow entering the combustion chamber. The combustion chamber can also grow carbon deposits. Decarbonizing solution is used to clean these up, though a liquid is used with cars that have MAF sensors and aerosols are used when a car does not.

PCV System:

The Positive Crankcase Ventilation system reduces engine HC emissions, keeps the crankcase cleaner, and makes engine oil last longer, but it requires maintenance every so often in order to work properly. It will be inspected and the PCV valve may be replaced. Also all related hoses will be checked. If the PCV valve is stuck-open or stuck-closed there can be high oil consumption.

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J and S Auto Care Specialists