How to Diagnose Poor Fuel Economy: Tips from the 1A Auto Mechanics
Is your car using too much gas? Having a car that has poor fuel economy means that your vehicle isn’t running efficiently. It also means that you’ll be making more trips to get gas and spending a lot more money at the pump. Whether you own a truck, SUV, or car; a sudden drop in fuel economy is never a good sign. It can cause your vehicle to lose power.
There are different reasons why your vehicle has poor fuel economy. It could be due to a mechanical issue that you need checked by a professional or a change in your driving habits. Whatever the case may be, you’ll need to first diagnose the car by taking a look at one of the most important parts – the air filter.
How important is an air filter to an engine?
Your engine air filter prevents dirt, dust, and other contaminants from reaching the engine. It also ensures that only clean air gets in, a very important component of the combustion process. A proper mix of air and fuel allows the engine to perform at its peak efficiency. If you have a car using too much gas checking for a dirty air filter is a great place to start.
Does a dirty air filter affect car performance?
An air filter that’s clogged or filled with dirt, sand or debris restricts the amount of clean air getting to the engine. This in turn affects the combustion process and as a result leads to bad gas mileage.
Think of it like running while wearing a mask over your nose. You may be able to run for a short distance but when it comes to prolonged movement, you will struggle. In a similar fashion, a clogged air filter causes the engine’s acceleration, torque, and power to suffer. The engine is forced to work harder than normal. This can be the cause of your car using too much gas.
How to Diagnose Poor Fuel Economy
Steps to Diagnosing Bad Fuel Economy
- Check the condition of your air filter
To check your air filter, you’ll need to first locate it under the hood. Most modern vehicles have it stored inside an air collector box near the front of the engine. Others have it placed where the air duct ends.
Take out your air filter and check to see if it’s dirty, clogged or full of debris. If it is, it may be the reason behind your vehicle’s bad gas mileage. You can try and rub off some of the dirt and debris from the filter but this won’t be helpful overall. The best solution is to replace the clogged air filter with a new one.
Avoid using any type of blowgun to blow out dirt from the air filter. This might spread the fibers that catch the dirt, leaving them unable to do it anymore. Very little of the debris will be filtered out and much of it will get to the engine.
- Clean inside the air collector box
Check inside the collector box for any crud. If you find a lot of waste material inside, you may have mice that spend half of their time in your house and the other half in your car. You’ll have to clean it all out before replacing your air filter.
Eliminate the mice infestation. Start by following through the air duct until you get to the mice’s entry point. You can wrap a moth ball inside a small bag and put it at this entry. The smell is going to keep the mouse out.
Alternatively, you could put a screen that can restrict the mice from getting through. Whatever you do, don’t put anything that will affect airflow. This could deprive the engine the right amount of clean air, leaving the problem of bad gas mileage unsolved.
- Check the Mass Airflow Sensor
If your engine air filter and air collector box are full of dirt and debris, you’ll also want to check for a contaminated mass airflow sensor. This is a device that has a bubble which reads the amount of air that’s getting pulled into the engine. It helps the vehicle know exactly how much clean air is getting through so that the engine can match it with the right amount of fuel.
To access the mass airflow sensor, you’ll need to unscrew or unplug it from the air filter housing duct. Check its bubble for any dirt or contamination. If your mass airflow sensor is dirty, it will not be able to read the correct amount of air getting through. It will run inefficiently and result in very poor fuel economy.
A dirty mass airflow sensor can be cleaned using an electronic parts cleaner. Just be careful not to damage any of the sensing elements as you remove contaminants and dirt.