The mass air flow sensor is a device without which normal engine operation is impossible. The performance of the mass air flow sensor directly affects the functionality of the power unit. How to determine if the flow meter is faulty and how to clean the mass air flow sensor - you can find the answers to these questions below.
Possible malfunctions of the mass air flow sensor: signs and causes
How to clean and rinse the mass air flow sensor? We will talk about this below, but first, let's look at the signs and causes of device malfunction. The parameters transmitted by the flow meter largely influence the formation of a combustible mixture, which is very important for any modern engine. If the device fails, this may also make it impossible to start the engine.
By what symptoms can you understand that it is time to change or clean the regulator:
- the appearance of the Check Engine indicator on the control panel;
- the fuel consumption of the car has increased;
- The power of the vehicle has decreased significantly; the car now needs more time to gain speed;
- the dynamics dropped, in particular when accelerating;
- the engine does not start, it is possible to start the power unit with great difficulty;
- If the car is idling or stopped at a traffic light, then the crankshaft speed may fluctuate.
As for the causes of the malfunction, there are several of them:
- The flow meter is clogged, this is quite normal, in this case you can wash it.
- The device is faulty; only replacement will solve the problem.
- Poor contact of the mass air flow sensor with the on-board network; this may be caused by damaged wiring.
Naturally, such symptoms of a breakdown may also indicate a malfunction of other systems and devices, which is why every car owner should be able to diagnose problems.
Compound
Designed to effectively remove oil, dirt, small fabric fibers and dust from the sensor without damaging it. The main components of MAF sensor cleaners are:
- Hexane, or its rapidly evaporating derivatives.
- An alcohol-based solvent (usually 91 percent isopropyl alcohol).
- Special additives that manufacturers (the main one is the Liqui Moly trademark) use to protect their copyrights. They mainly affect smell and density.
- Carbon dioxide as a retardant for the composition in a can.
The mixture is usually sold in the form of an aerosol, so the substances must be highly dispersed, not irritate the skin and not have a harmful effect on the environment. The physical and mechanical characteristics of the most commonly used compounds (for example, Luftmassensensor-Reiniger from Liqui Moli) are:
- Density, kg/m 3 - 680...720.
- Acid number – 27…29.
- Ignition temperature, º C – not less than 250.
Sensor diagnostics
There are several ways to test the performance of a flow meter; let’s consider the easiest and fastest one. To carry out diagnostics, you will need to disconnect the power connector from the mass air flow sensor, but the engine must be running. When the contact is disconnected, the control unit will begin to operate in emergency mode. Accordingly, as a result of this, the fuel dosage will be carried out according to the parameters that were received from the throttle.
It must be taken into account that in this case the speed of the power unit can increase sharply to 1500 per minute. However, this does not happen in all cars. With the flow meter turned off, you need to drive the car a little. If you notice that the performance of the power supply has improved, then most likely you need to change the mass air flow sensor (video author - Xie Dan).
Features of application
The nuances are determined by the brand of car that has a mass air flow sensor. In particular, the choice of installation tools used to unscrew the fasteners depends on this.
You should never use MAF cleaner while the engine is running or the ignition is on. This can cause serious damage to the sensor, so it should only be disconnected when there is no current in the system.
Before spraying, place the sensor on a clean towel. Cleaning must be done so as not to touch any of the sensitive elements with the nozzle of the aerosol head.
To improve the cleaning effect, it is recommended to pre-wash the surface of the air flow sensor. To do this, place the unit in a plastic bag filled with isopropyl alcohol and shake vigorously several times. After drying, apply mass air flow sensor cleaner.
Purifier selection options
How to clean the flow meter? The modern market offers many products for cleaning regulators; let’s look at the most effective options:
- Liqui Moly. This manufacturer, as you know, produces not only cleaning products, but also motor and transmission oils, as well as other types of liquids. If you believe the official information provided by the manufacturer, then this product belongs to the high-quality category. Accordingly, the cost of such a MAF cleaner will also be high. In fact, Liqui Moly cleaners cope with their tasks quite effectively - this product perfectly removes dirt from the sensor. If the flow meter was in working order at the time of cleaning, then after that it will work for a long time. The use of Liqui Moly is relevant in both gasoline engines and diesel power units.
- Alternatively, you can use alcohol to clean the device. This method is considered one of the oldest, but nevertheless the most effective. Due to its chemical properties, alcohol is good at removing clogs that accumulate on the sensitive component of the air flow sensor. Despite its effectiveness, today this method is not used so often and is usually used by unscrupulous technicians at service stations. The client pays for a special substance, for example, Liqui Moly, and in fact the cleaning is carried out using alcohol.
- The next option is fluid for carburetor engines. This option is considered one of the most effective and frequently used. Using carburetor fluid, you can effectively clean it, and as practice shows, such a product allows you to remove all contaminants.
- Another product sold in spray form is Liquid Key. This cleaner is used to remove all kinds of contaminants, not only from the flow meter, but also from other mechanisms and components.
- A universal tool for performing many tasks is WD-40. This liquid is used by our compatriots to clean all kinds of components, remove rust, get rid of squeaks, etc. Not so long ago, our car enthusiasts began to use it to clean flow meters (the author of the video is the Gen channel MB W140 Germany).
Liqui Moly
How to clean the MAF sensor? One option is cleaning fluid from Liqui Moly. The company is known to many car enthusiasts as a manufacturer that makes only high-quality products for cars. In addition, the ratio between reliability and price is at an optimal level. As for the use of liquid for cleaning the mass air flow sensor, most vehicle owners have already become convinced of its effectiveness. This has not been proven by a single procedure. And if the sensor is in working condition, then even after cleaning it will last no less.
The liquid can be used for both diesel and gasoline engines.
Instructions for washing the mass air flow sensor
Cleaning the flow meter can be done in a garage; there is nothing complicated about it.
Depending on the car model, the procedure for removing the sensor can be carried out in different ways; consider an example of cleaning with a domestic “Ten”:
- First, you should turn off the ignition and, just in case, reset the battery terminal. Open the hood and find the mass air flow sensor, then disconnect the connector from it. There is a pipe connected to the flow meter; it must be disconnected. Using a wrench, you need to unscrew the screw that secures the device to the air filter, or rather, to its housing.
- The flow meter itself is removed from the corrugation; in the case of the “ten”, an asterisk wrench is required to dismantle the sensor. Use it to unscrew the screws and then remove the device from the seat.
- If, after removal, you notice that there is an oil deposit on the device, you will need to rid the case of this. Any product from those described above is suitable for cleansing. As practice shows, there is no fundamental difference between these means.
- On the sensitive element, usually made in the form of a film, there are several controllers; they are made in the form of a wire and mounted on resin. Using the same cleaning agent, you will need to carefully, not in abundance, spray it on the sensitive element. At this stage, you should act as carefully as possible, since there is a possibility of damage to the film. After the sensitive part has been treated, you need to wait a little until the product takes effect. If there is a lot of contamination, then it may make sense to repeat this procedure once or twice. In order to ensure faster evaporation of the substance, you can use a pump or compressor device. But keep in mind that too much pressure can destroy the sensitive component, so don't overdo it.
Photo gallery “How to clean yourself”
Price issue
The cost of Liqui Moly cleanser is currently about 700 rubles. A cheaper analogue, liquid for cleaning carburetors, will cost the buyer about 70-100 rubles. As for WD-40, the cost of a 100 ml can today will be approximately 180-220 rubles.
How to use?
Cleaning the air flow sensor must be performed whenever the air filters are changed. The sensor itself is located in the air channel between the filter box and the throttle body. Using a special tool, the device is carefully disconnected from the electrical connectors.
Some brands of cars are equipped with mechanical flow meters. They do not have measuring wires, and therefore are less sensitive to the thoroughness of dismantling.
Next, 10 to 15 sprays are applied onto the wire or sensor plate. The composition is applied to all sides of the sensor, including terminals and connectors. Platinum wires are very thin, so they cannot be wiped. After the composition has completely dried, the device can be returned to its original place. A good spray should not leave marks or streaks on the surface of the air flow sensor.
What kind of device is this?
Such an element is present in any modern car, since the era of carburetor engines has passed and an electronic control unit (ECU), or controller in other words, is responsible for many operations. Many drivers even call him “the brain.”
The mass air flow sensor is used to measure the amount of air supplied to the engine. However, this device does not measure its volume, but only determines how much mass passes per unit of time, sending data to the ECU. In turn, the controller “understands” how much air has entered the cylinders at each moment of time, and depending on this, adjusts the fuel supply. As a result, the engine runs smoothly and without interruption.
Beginners may be interested not only in whether the mass air flow sensor can be cleaned, but, in fact, where it is located. Typically, this device is located in the area between the air filter housing and the pipe that goes to the throttle valve. It is equipped not only with gasoline, but also with diesel power units.
