The heart of the car - the engine, requires constant attention from the owner. In order for him to be able to obtain information on the state of the device, control systems are provided in each machine. Among them is the oil pressure sensor.

It would seem, why pay so much attention to some small light bulb, which then lights up, then goes out? Everything is not as simple as it may seem to ignorant people. In such a tiny mechanism is hidden information about the state of the engine, the presence or absence of the required amount of lubricant. Most often, the bulb lights up precisely when the motor is experiencing an oil starvation. But, unfortunately, this is only one of the problems. Causes of emergency blinking can go much deeper and sometimes difficult to find.

The basis of the sensor is that the internal elastic membrane begins to move from the oil pressure. So basically all sensors work. The diaphragm shift parameters are visible on the resistor, which is read by special equipment and displayed on the manometer.

On the website Zakupka.com you can buy a new or used sensor, which is quite inexpensive, but performs its function well - signaling about breakdowns. We have devices for models VAZ 2106, 2110, 2112, 2114, Audi, Gazelle 4216, Opel, Renault, Volkswagen, UAZ, Chevrolet, Priora, Ford, Nissan and many other cars.

How does this happen?

Sensor replacement can be done independently or by experienced service station staff. The work is non-durable, so you will get your car back in a few hours.

Many drivers do not even know where this part is located, as its location in different cars may differ. They also differ in their device. For example, in VAZs with a diesel engine a mechanical system is used. There are similar devices with magnetic drive or floating point, pneumatic. They differ in price and features of work.

Replacement can be made only after the new sensor has been tested for suitability. Moreover, if the inspection revealed no visible defects, this does not mean that it is working. Need a comprehensive diagnosis of the details. When installing a new device, it is very important to choose a high-quality oil that will ensure flawless system operation, otherwise after a while you will have to replace it again.

Do not ignore sensor readings

This can lead to a serious problem with the engine or lead to its complete failure. Knowing the reasons for the bright light, you can eliminate the problem in the mechanism.

Most often it is:

    insufficient amount of oil in the lubrication system;

    damaged connection pins;

    engine oil pressure is insufficient;

    contacts have oxidized;

    the sensor itself has failed.

How to check what exactly happened to your car? To begin to fill in a sufficient amount of oil, try to replace it with another, better. Inspect all contacts responsible for the operation of the system, and use a pressure gauge to check the health of the sensor.

The installation of a new oil pressure sensor in various GAZ, Kalina, Toyota, Honda, KAMAZ, Peugeot, Nexia, Mercedes, Mazda, Golf cars is made according to certain schemes. To buy a suitable product, carefully review its photo and description in our online catalog. If you have any questions regarding the purchase, hurry to ask them to sellers.

Choose a quality product for the perfect work of your car.

The oil pressure sensor is a device that converts mechanical force into an electrical signal of different voltages, which, after decoding, allows you to judge the pressure in the lubrication system in real time.

Why do I need a sensor to control engine oil pressure

The oil supply to the friction points in the engine is carried out in different ways - including by spraying (for what), for which pressure must be created.

In order to save money when tuning the engine in a car that does not have a standard device for monitoring oil pressure, you can purchase and install a budget device from a Russian truck

In the case of its reduction, which may occur due to a decrease in the amount of oil in the system or failure, the friction of the nodes increases, which leads to accelerated wear or jamming of parts. To prevent these consequences in time, a pressure sensor is built into the lubrication system.

Reading the signal can be implemented in different ways. Most often, the driver does not see detailed readings and can be guided only by triggering a warning device with an icon depicting an oiler on the dashboard in the event of a decrease in pressure to a critical level. In some cars, the engine oil pressure is displayed on a separate scale. In the most modern cars, the pressure sensor readings are used not only to monitor the state of the engine, but also to optimize its operation.

Oil pressure sensor device

The work of most pressure sensors is based on the principle of converting one type of energy into another. The primary transducers emit a mechanical force that either directly affects the sensitive element of the measuring device (dial gauges) or is converted into an electrical signal. In modern cars use pressure sensors of the second type, as an electrical signal can.


Old style sensor device

The classic pointer instrument on the dashboard of old cars (for example,) in combination with a sensor is a kind of pressure gauge. In the old sample devices, the measurement of oil pressure was based on the deformation of the elastic sensing element (membrane). Deforming, the membrane pressed the rod, compressing the fluid in a sealed tube. At the other end, the fluid pressed against the other stem, which lifted the mechanical needle. Such an automobile device is called a differential pressure gauge.

Depending on the country of production, the scale of oil pressure readings can be graduated in Pascals, Newtons per square meter, bars, atmospheres or kilogram-forces per square centimeter.

Modern oil pressure sensor

In more modern models, the measurement is carried out by a transducer mounted on the cylinder block, and the readings are transmitted as an electronic signal to or on an electronic scale. For this purpose, an intermediate transducer is provided in the sensor housing, which converts the mechanical force into an electrical signal.

In such devices, the role of a sensitive element is performed by a rigid metal membrane equipped with a resistor, which changes resistance in response to deformation. The resistance is converted by the measuring circuit into an electrical signal, which is transmitted via wires or via a CAN bus.

Operation of oil pressure sensor

The oil pressure at idle should be around 2 bar and in good condition and warmed up to the engine's operating temperature. The oil pressure at high revs (as a rule, for most engines is.) Is from 4.5 to 6.5 bar. If the pressure fluctuates within acceptable limits, the contacts in the electrical transducer circuit are open and the oil on the dashboard is off.

The average level of oil pressure is affected by the height of the point where the car is above sea level

In general, the oil pressure sensor is reliable and rarely fails. More often, trouble happens with a seal that prevents oil from seeping out of the cylinder block to the outside. Its condition must be monitored, since in case of oil leakage it gets on the hot block, which can lead to fire.

Causes of oil pressure drop in the system

Too low or too high pressure always indicates a malfunction in the engine or at least the oil pump.

If the pressure is high, there may be a blockage somewhere in the system. The oil channels in the walls may be blocked, or it may be clogged with wear products.

If the pressure is too low, it may be a weakening of the spring or general wear of the oil pump.

Situations of incorrect pressure may be different, and they are not necessarily associated with breakdowns. For example, when starting the engine, the pressure in the system in which it circulates may be normal, and after warming up to operating temperature, it will drop to almost zero. This is due to a drop in the density of the oil during heating.

  Details

The system of emergency pressure of oil, is very important monitoring system in the car. If this system does not work, then there is a high probability, in the event of a malfunction in the engine, to spoil it. Therefore, it is necessary to take responsibility for controlling oil pressure. One of the units of control is itself oil pressure sensor.

Figure 2 - Oil pressure control sensor.

As for the first, everything is quite simple there.

Figure 3 - Membrane inside the oil pressure sensor.

Inside the sensor is a membrane (Figure 3) that is sensitive to oil pressure. When we switch on the ignition, the oil pressure in the system is absent, the contacts 3 inside the sensor are closed (Figure 4a). Our electric circuit is closed, therefore, the lamp of emergency oil pressure is on, saying that the control system is working. We start the engine, the oil pressure increases, acting on the membrane 4. The membrane is formed and pushes the pusher 1b, which breaks the contacts and the lamp goes out. If, for some reason, the pressure in the system drops, to which the sensor is designed, the diaphragm returns to its usual position and the pusher closes the contacts again. The lamp lights up, telling us about the drop in oil pressure in the system.

Fig 4 - Scheme of operation of the emergency oil pressure sensor.

For checking the oil pressure sensor we need a multimeter, a pump with a manometer and the sensor itself. Multimeter set on dialing the circuit. We get up the ends of the device on the sensor. It should show zero resistance (short). Next, without removing the ends of the device from the sensor, let's make the pump swing. At this moment, when we pump the pump, the chain should break and the device should show infinity. If you have done the previous procedure, you get the same result, then the sensor can be considered serviceable.

The second type of sensors is arranged as follows:

Figure 5 - Sensor control the oil pressure in the section.

Inside there is a slider 2 (Figure 5), which moves along the plate with nichrome wire 1 wound on it. And depending on the pressure, the resistance of the sensor changes. Under the action of oil pressure, the membrane 3 (Fig. 6) is deformed by moving the pusher 4, which in turn affects the resistance changing mechanism 2. Given this resistance, the arrow on the device 1 shows us the corresponding pressure.

Figure 6 - Scheme of oil pressure control.

    If we want to make sure that our sensor is working within the required pressure limits, then we can do the following experiment:
  • We take a small piece of hose of the desired diameter, on the one hand we need to attach the same adapter as on the pump, on the other hand we insert the sensor. If the hose is slightly larger in diameter, it should be pressed on top of the wire. The system must be tight.
  • We need a graph (or just a plate with checkpoints), which should reflect at what pressure, what should be the resistance on the sensor. Such a schedule should be in the manual for your car.
  • Next, take the spare tire and pump it up to the desired pressure. Here, of course, we will not be able to get rid of all the control points, but we can make some conclusions about the sensor operation.

If you check the performance of the sensor (removed from any used engine) before installing it on your car, then the sensor should also be checked for tightness. We dissolve the soap solution. Pressurizing the pump, wet the seamed joints on the sensor with a solution. If the soap solution does not foam, then everything is in order, such a sensor can be safely put on the engine.

The performance of the engine of any car depends on the availability of engine lubrication and pressure created by the oil pump. In order for the driver to control these important parameters, an appropriate indicator and an emergency lamp flashing red are installed on the dashboard of the “classics” VAZ 2106. Both indicators receive information from a single element built into the engine, the oil pressure sensor. The detail is simple and, if necessary, easily changed by hand.

Purpose of the sensor of control of pressure of oil

All moving and rubbing parts of the power unit are constantly washed by the lubricant supplied by the gear pump from the engine oil pan. If, due to various reasons, the supply of lubricant stops or its level drops to a critical level, the motor will face a serious breakdown, or even more than one. The result is a major overhaul with the replacement of crankshaft bearings, cylinder-piston group and so on.

To protect the owner of the car from the specified consequences, in the classic models of "Zhiguli" there is a two-level control over the engine lubrication system operating according to the following algorithm:

Malfunctions leading to pressure drop - breakdown or wear of the oil pump, full generation of crankshaft bearings or crankcase breakdown.

The main role in the work of the system is played by the sensor - an element that fixes the oil pressure in one of the main channels of the engine. The indicator and the pointer are merely means of displaying information transmitted by a pressure gauge.

Location and appearance of the device

The sensor mounted on the classic model VAZ 2106, consists of the following parts:

  • element in the form of a round metal barrel with one terminal for connecting the wire (factory name - ММ393А);
  • the second part is a membrane switch in the form of a nut with a contact at the end (designation - ММ120);
  • steel tee, where the above parts are screwed;
  • sealing bronze washers.

The MM393A large “barrel” is designed to measure pressure, the “nut” with the MM120 terminal fixes its absence, and the tee is a connecting element that is screwed into the engine. The location of the sensor is on the left wall of the cylinder block (if you look in the direction of the vehicle) under the spark plug No. 4. Do not confuse the device with the temperature sensor installed above in the cylinder head. Both contacts are connected wires leading inside the cabin, to the dashboard.

In the later models of the “classics” VAZ 2107 the arrow pointer on the dashboard is missing, only the warning lamp is left. Therefore, a stripped-down version of the sensor without a tee and a large keg is used.

Device and connection diagram

The task of the membrane switch, made in the form of a nut with a terminal, is to close the electrical circuit with a control lamp in time when the lubricant pressure drops. The instrument consists of the following parts:

  • metal case in the form of a hexagon;
  • contact Group;
  • pusher;
  • measuring membrane.

The element is included in the circuit according to the simplest scheme - sequentially with the indicator. The normal position of the contacts is “closed”, therefore after turning on the ignition the light comes on. In the internal motor there is a pressure of the oil coming to the membrane through the tee. Under the pressure of the lubricant, the latter presses the pusher, which opens the contact group, as a result, the indicator goes out.

When one of the malfunctions occurs in the engine, causing a decrease in the pressure of the liquid lubricant, the elastic membrane returns to its original position and the electrical circuit closes. The driver immediately sees the problem of a flashing “control”.

The device of the second element - “barrel” under the name MM393A is somewhat more complicated. The main role here is also played by an elastic membrane connected to an actuator - a rheostat and a slider. The rheostat is a coil of nickel-chrome nickel wire of increased resistance, and the slider is a moving contact moving along the turns.

The electrical circuit for connecting the sensor and the pointer is similar to the first one - the rheostat and the device are in a circuit in series. The algorithm works as follows:

  1. When the driver turns on the ignition, the voltage is supplied to the circuit. The slider is in the extreme position, and the winding resistance is maximum. Arrow device is kept at zero.
  2. After starting the engine, oil appears in the channel, coming through the tee into the “barrel” and pressing on the membrane. It stretches and the pusher moves the slider along the winding.
  3. The total resistance of the rheostat begins to decrease, the current in the circuit increases and causes the pointer arrow to deflect. The higher the lubricant pressure, the more the membrane will stretch and the less the coil resistance, and the device will notice an increase in pressure.

To reduce the oil pressure sensor reacts in the reverse order. The force on the membrane is reduced, it is thrown back and pulls the slider. That includes in a chain new turns of a winding of a rheostat, resistance increases, the arrow of the device falls to zero.

Video: how much pressure should be shown a working device

How to check and replace item

During long-term operation, the internal parts of the sensor wear out and occasionally fail. The malfunction manifests itself in the form of false indications of the indication scale or a constantly burning emergency lamp. Before drawing conclusions about the breakdowns of the power unit, it is highly desirable to check the performance of the sensor.

If the engine is on fire when the engine is running, and the pointer has dropped to zero, your first action is to stop the engine immediately and do not start until a problem is detected.

When the lamp lights up and goes out in time, and the arrow does not deflect, you should check the operability of the oil sensor - pressure meter ММ393А. A wrench size 19 mm and a pressure gauge with a scale up to 10 Bar (1 MPa) will be required. To the gauge you need to fasten a flexible pipe with a threaded tip M14 x 1.5.

The verification procedure is as follows:

  1. Stop the engine and allow to cool to 50-60 ° C, so as not to burn your hands during operation.
  2. Disconnect the wires from the sensors and turn them out with a 19 mm wrench with a tee. Note, at the time of disassembly from the unit may leak a small amount of oil.
  3. Screw the threaded part of the nozzle into the hole and tighten it carefully. Start the engine and observe the gauge.
  4. Oil pressure at idle is from 1 to 2 Bar, on worn out engines it can drop to 0.5 Bar. Maximum readings at high speeds - 7 Bar. If the sensor produces other values ​​or is at zero, you need to buy and install a new spare.

On the road, it is more difficult to check the oil sensor of the VAZ 2106, since there is no pressure gauge at hand. To make sure there is lubricant in the motor channels, unscrew the element, disconnect the main ignition wire and rotate the crankshaft with the starter. At the serviceable pump oil will splash out from an aperture.

If the arrow on the instrument scale shows normal pressure (in the range of 1-6 Bar), but the red lamp is on, a small MM120 membrane sensor has clearly failed.

When the light does not light at all, consider 3 options:

  • light bulb burned out;
  • breakage;
  • the small sensor in the form of a hexagon has become unusable.

The first 2 versions are easy to check by dialing with a tester or multimeter. The serviceability of the membrane element is tested as follows: turn on the ignition, remove the wire from the terminal and close it to the vehicle ground. If the lamp comes on, feel free to change the sensor.

Replacing is done by unscrewing a large or small sensor with a wrench. It is important not to lose the sealing bronze washers, as they may not be included with the new part. Remove motor grease from the hole with a rag.

Both gauges are not repairable, only replaceable. Their metal bodies, capable of withstanding the oil pressure of a running engine, are hermetically sealed and do not disassemble. The second reason is the low price of spare parts for the VAZ 2106, which makes such repairs meaningless.

Video: How to check the lubrication pressure gauge

Video: replacement of the sensor VAZ 2106

Functions and pointer operation

The purpose of the device built into the torpedo to the left of the tachometer is to display the pressure level of the engine oil, guided by the sensor. The principle of the pointer resembles the work of an ordinary ammeter, which reacts to a change in the current in the circuit. When the mechanical rheostat inside the measuring element changes the resistance, the amperage increases or decreases, deflecting the arrow. The scale is calibrated in units of pressure corresponding to 1 Bar (1 kgf / cm 2).

The device consists of the following main elements:

  • round body;
  • switch mechanism with permanent magnet and windings;
  • control lamp connected to the corresponding sensor by a separate line;
  • scale with backlight;
  • compensating resistor;
  • connecting wires with connector.

Zero device readings correspond to a 320 Ohm circuit resistance. When it drops to 100-130 ohms, the arrow keeps at 4 bar, 60-80 ohm - 6 bar.

The pressure indicator of the engine lubricant "Zhiguli" is a fairly reliable element, breaking very rarely. If the arrow does not want to leave the zero mark, then the sensor is usually the culprit. When you doubt the performance of the indicating device, check it with a simple method: measure the voltage at the connection terminals of the oil sensor MM393A with the engine running. If the voltage is present and the arrow is at zero, the device should be changed.

The monitoring system for VAZ 2106 oil pressure with two sensors and a mechanical indicator is simple and reliable in operation. Despite the outdated design, motorists often buy and put these gauges on other, more modern cars, equipped from the factory only with a control indicator. Examples - the updated VAZ "Seven", Chevrolet Aveo and Niva.

In a modern engine, oil pressure readings are necessary both for the purpose of monitoring and for optimizing the operation of the engine. The oil pressure sensor is a device that converts a mechanical force into an electrical type signal. After it is decrypted by the vehicle control unit, the driver receives information about the pressure in the lubrication system, displayed on the dashboard in real time.

Purpose

Experienced motorists know that the oil supply to the places where there is friction of the internal elements of the motor is carried out in various ways, one of which is spraying. To perform this function is required to create a strong pressure.

When it is lowered, which is possible when the oil pump fails or the amount of oil in the system decreases, the friction of the nodes increases, resulting in jamming or accelerated wear of parts. To avoid such consequences and timely warn them, a special element is introduced into the lubrication system - a pressure sensor.

If you are interested in where the oil pressure sensor is located on your car, you should open a book on the repair and maintenance of the car that you own. As a rule, the oil pressure sensor on domestic cars, in particular LADA cars, should be searched behind the cylinder head, not far from the timing belt casing.

Modern type oil pressure sensor

Finding out where the sensor is located, which is responsible for the timely notification of the driver about lowering the oil level, you should understand its structure. Modern models are a converter mounted in the cylinder block. His readings are transmitted to the electronic scale or to the on-board computer in the form of a special electronic signal. To accomplish such a task, a so-called intermediate converter is built into the sensor body, which converts the force of a mechanical type into an electrical signal.

The role of the sensing element in such devices is performed by a rigid metal membrane. It, in turn, is equipped with a resistor, which is characterized by its ability to change resistance in response to the deformation. Then, resistance using a special measuring circuit is converted into an electrical signal transmitted via a CAN bus or through wires.

Causes of oil pressure drop in the system

Always about the failure of the motor indicates too high or very low oil pressure. At best, it may turn out that the engine is working properly, and the oil pump was to blame, but you have to be prepared for even the most unpleasant consequences.

If the pressure is too high, the cause may be:

  • blockage in the lubrication system;
  • blockage of oil channels located in the walls of the cylinder block;
  • clogging of the pressure reducing valve with wear products.

In the case of very low pressure in the system, this could be:

  • loosen the oil pump spring;
  • wear all its designs.

Having learned the location of the oil pressure sensor, its design features and structure, the most important thing left is to make the correct diagnosis as to why the pressure in the lubrication system stopped responding to normal. There are a lot of reasons for incorrect oil pressure, and not all of them speak about serious breakdowns.

The pressure in the system when starting the engine in the winter time may be normal. But it is necessary to warm up the engine to the operating temperature, the oil pressure can drop to almost zero. This is easily explained by the drop in oil density that occurs when it is heated.

Video

See how the oil pressure sensor is removed at the VAZ 2112: