Good day everyone. In today's article, we are considering a typical problem - the oil pressure in the ZMZ 406 engine has disappeared. Unfortunately, this is a fairly common problem and there are quite a few typical reasons in the article, we will analyze all the reasons and how they manifest themselves.

Let's start with a description of the design of the ZMZ 406 lubrication system:

The oil pump is driven by the intermediate shaft through a hexagon. The oil pump is equipped with a pressure reducing valve that relieves excessive pressure oil back into the crankcase. From the oil pump, oil is fed through a filter into the main oil line, from which the crankshaft journals and the intermediate timing shaft bushings are lubricated. Also from the main line there is a channel to the cylinder head and to the hydraulic tensioners. In the cylinder head, in turn, 2 oil channels are drilled parallel to the camshafts. Through these channels, oil is supplied to each camshaft journal and to each of the 16 hydraulic lifters.

Most problem areas in the lubrication system - a pressure reducing valve, intermediate shaft bushings and hydraulic chain tensioners, but first things first…

The oil pressure in ZMZ 406 suddenly disappeared.

There are only two reasons in this case - the oil pump pressure reducing valve is stuck in the open position. It looks like this:

This usually happens due to dirt getting under the pressure reducing valve. Even the smallest crumb wedges the valve and it does not close completely.

The second typical reason is a breakdown of the oil pump drive.

The drive looks like this:

It should be noted that these two malfunctions are extremely rare and they occur when the oil change interval is not observed and when operating on oil that does not correspond to the climate.

The oil pressure in the engine disappeared gradually.

This is the most typical problem, it is associated with natural wear and tear, periodic maintenance and design miscalculations.….

The most common reason is oil filter.

During the operation of the gazelle (2705), I changed the filter every 5,000 km, and changed the oil every 10,000 km. The reason is that when running on gasoline, the oil quickly darkens and a bunch of dirt forms in it that clogs the filter. When operating on gas, this problem is not observed!

The second most popular reason is the ingress of gasoline into the fuel.

It is fair, in the main, the share of carburetor versions of the 406 engine (when the fuel pump membrane breaks, gasoline inevitably gets into the oil), but this is a completely possible scenario on an injection engine with a running nozzle.

The third reason is wear and tear.

Due to wear, gradually, all gaps in friction pairs increase.

• The main place where pressure is lost is the intermediate shaft. Many do not change the intermediate shaft support bushings even with a major overhaul, but it is in these bushings that most of the pressure is lost.
• The second most popular place is worn-out hydraulic chain tensioners.
• The third place is the wear of the cylinder head and the wear of the camshafts .. The fact is that on the 406 engine, the camshaft beds are located in the body of the cylinder head and at the slightest “removal” of the plane, the wear of the bed increases significantly - the result is a loss of pressure. When the shaft itself is worn, the gap in the friction pair increases and pressure is also lost.
• The fourth place is the wear of the oil pump. When worn, the pump will not pump enough oil into the engine lubrication system and there will be no oil pressure. You can deal with this by reassembling the pump with the output of its planes or replacing the oil pump assembly with an oil pump from ZMZ 514 (it is for a diesel engine and has increased productivity).
• Fifth place - valve clearance hydraulic compensators, compensators in the cylinder head 16 (by the number of valves) and with high mileage their beds are also subject to wear, but the service life of the compensator beds, as a rule, exceeds the service life of the cylinder head.

The fourth reason is the oil bypass valve springs.

A bypass valve is installed on the oil pump housing, it opens when the oil pressure is high. The fact is that over time, the valve springs weaken and part of the oil pressure is lost on this valve. It's okay to put a couple of washers under the valve spring when overhauling the pump.

About the oil cooler.

On some modifications of the ZMZ 406, a radiator for cooling the oil is installed, but in reality this design is practically not used because it reduces the pressure of the already diluted oil and has low-quality taps that constantly run. The oil cooler was implemented relatively competently on the ZMZ 405 (a thermal valve is used), but even there its effectiveness is doubtful. In most cases, it is advisable to plug the oil cooler and use a more thermally stable oil (tested for personal experience operation gas 2705 with a mileage of 470,000 km).

Ways to increase oil pressure in the ZMZ 406 engine during operation.

• More frequent oil filter changes.
• Replacing the oil pump with a pump from ZMZ 514 part number 514 .1011010
• Disabling the oil cooler or replacing it with a heat exchanger.
• Changing the oil to a thicker and higher quality one, it is the viscosity at high temperature that is important.
• Putting 2-3 washers under the oil bypass valve spring

Ways to increase oil pressure during overhaul.

Be sure to re-bush the intermediate shaft and turn the bushings correctly.

Install jets in the lubrication system.

The fact is that there are several places in the engine where a lot of pressure is lost, and in order to increase the life of the engine during a major overhaul, it makes sense to plug some channels in the lubrication system with carburetor jets! The best option turned out to be jets drilled with a 2 mm drill.

So, here are these places and options for their jicling:

Hole for oil pump shaft lubrication

Chain tensioners (upper and lower)

That's all for me. I hope that the problem of missing oil pressure in the 406 engine will never bother you again.

Any engine internal combustion lubrication of rubbing parts is necessary, and the engines of the ZMZ family are no exception in this regard. Without constant lubrication, such an engine will work for a maximum of an hour, after which it will simply jam. Its cylinders and valves will be seriously damaged, and it will be extremely difficult to repair such a breakdown. Therefore, the oil pressure in the ZMZ engine is the most important indicator that the car owner must carefully monitor. But on domestic cars with ZMZ engines, oil pressure very often disappears. Let's try to figure out why this happens and how it can be eliminated.

About ZMZ engines

Before talking about oil pressure, it is worth introducing the reader to the engine itself. ZMZ engines are produced by the Zavolzhsky Motor Plant. They have 4 cylinders and 16 valves.

ZMZ engines are produced by the Zavolzhsky Motor Plant

These motors are installed on Volga, UAZ, GAZelle, Sobol cars. The family includes motors ZMZ-402, 405, 406, 409, 515 and a number of their special modifications. ZMZ engines have their advantages:

• good maintainability;
• simplicity of the device;
• low demands on the quality of fuel.

But there are also disadvantages:

• the timing drive is very bulky;
• the reliability of the chain tensioner in the timing drive leaves much to be desired;
• piston rings have an archaic design. As a result, large losses of lubrication and power failures are observed;
• the overall quality of casting and heat treatment of individual engine parts is getting worse every year.

Oil pressure rate in ZMZ engines

The pressure in the lubrication system is measured only on a well-heated engine running on Idling. The speed of rotation of the crankshaft at the time of measurement should not exceed 900 rpm. Here are the ideal oil pressure standards:

• for motors ZMZ 406 and 409, a pressure of 1 kgf / cm² is considered ideal;
• for motors ZMZ 402, 405 and 515, the ideal pressure is 0.8 kgf / cm².

It should also be noted here that the highest pressure in the lubrication system of the ZMZ engine can theoretically reach 6.2 kgf / cm², but in practice this almost never happens. As soon as the oil pressure reaches 5 kgf / cm², the pressure reducing valve opens in the motor and the excess oil goes back to the oil pump. So the oil can reach a critical point only in one case: if the pressure reducing valve is stuck in the closed position, and this happens extremely rarely.

Oil pressure check

The oil pressure is displayed on dashboard car. The problem is that it is far from always possible to trust these figures, since devices can also fail and begin to give incorrect readings. It often happens that the oil pressure is normal, and the instruments show that there is no pressure at all. For this reason, it is advisable to simply inspect the car. Here's how it's done:

If all of the above measures did not give a result, and the reason low pressure not identified, the last way remains: use an additional pressure gauge.

Signs of low oil pressure

If the oil pressure in the engine has dropped sharply, it is impossible not to notice this. Here are the main signs that something is wrong with the engine lubrication system:

• The motor began to overheat quickly. At the same time, there is more exhaust gas, and the exhaust is black, which is especially noticeable when the car picks up speed;
• bearings and other parts subject to intense friction began to wear out very quickly;
• the engine began to knock and vibrate. The explanation is simple: there is little lubrication in the motor, the rubbing parts gradually wear out and the gaps between them increase. In the end, the parts become loose, begin to knock and vibrate;
• burning smell in the cabin. If the oil pressure is reduced, it begins to rapidly oxidize and burn out. And the driver smells the products of combustion.

Causes of low oil pressure and their elimination

First of all, it should be noted that a drop in oil pressure is a malfunction that is a common "illness" for all engines of the ZMZ family, regardless of their model. There are no special nuances associated with this malfunction and characteristic of a particular engine from the ZMZ family. For this reason, the reasons for the drop in oil pressure in the ZMZ-409 engine, which is by far the most popular in our country, will be discussed below. It should also be said here that the most common reason for a drop in oil pressure is an incorrect viscosity index, aka SAE. Due to this driver error motor oil in hot weather it can become too thin. Or vice versa, in hard frost it can thicken quickly. Therefore, before looking for a problem in the motor, the car owner should ask himself a simple question: did I fill in the oil?

Sudden drop in engine oil

If the oil pressure suddenly disappears in the ZMZ engine, then this can happen for two reasons:

It should also be noted here that the above breakdowns occur quite rarely. In order for this to happen, the driver must absolutely “start” the engine and not change the oil in it for years, or use a lubricant that is not suitable for viscosity for a long time.

Gradual drop in oil pressure

This problem is very common in all engines of the ZMZ family, without exception. It can arise due to many factors: these are the design errors mentioned above, and improper maintenance, and the natural wear of parts, and much more. We list the most common causes of a gradual drop in oil pressure:

• oil filter wear. Gazelle drivers strongly recommend changing these filters every 5-6 thousand km, and changing the oil every 10 thousand km. If this is not done, in the oil, no matter how good it is, a dirty sediment appears, which gradually clogs the oil filter. And the driver at this moment observes the above signs of a drop in oil pressure;

  Oil filters on ZMZ engines should be changed as often as possible

• general engine wear. First of all, this applies to the intermediate shaft, on which the main pressure losses occur. This happens due to wear of the shaft bearing bushings. The hydraulic chain tensioner may also wear out, which also does not differ in durability. In addition, the cylinder head itself and the camshafts often wear out. At the slightest wear in this system, the pressure begins to drop, and oil consumption gradually increases. A worn out oil pump can also cause a pressure drop, which is simply not able to supply enough lubricant to the motor. And finally, the hydraulic compensators on the valves can fail, which also reduces the lubrication pressure. There is only one solution to all of the above problems: overhaul engine;
• valve wear. The pressure reducing valve has a spring that can weaken over time. As a result, part of the oil goes back to the oil pump, which leads to a decrease in oil pressure. Some motorists solve the problem simply: they put a couple of small washers under the spring in the valve. But this, as you might guess, is only a temporary measure. And the only right decision is to replace the pressure reducing valve with a new one (you won’t be able to buy a new spring for the valve - they are not sold separately);

  Spring - the main component of the pressure reducing valve in the ZMZ motor

• oil cooler leak. Radiators in which the oil is cooled are on many cars with ZMZ engines. However, these radiators are used extremely rarely, as their quality leaves much to be desired. Of particular note is the oil cooler valve. This faucet is constantly flowing. Solution: stop using an oil cooler, because when correct selection oil, the need for this device simply disappears. Or the second option: put a high-quality valve on the radiator (preferably a ball valve, made in Germany, but by no means Chinese).

Video: looking for the cause of the drop in oil pressure in the ZMZ engine

So, there are many reasons that cause a drop in oil pressure in engines of the ZMZ family. Some of them are the result of "congenital diseases" of this motor. Others are the result of the carelessness of the driver himself, and still others are the result of banal mechanical wear. Most of these problems can be fixed on your own, but the overhaul of the motor will have to be entrusted to a qualified specialist.

Lubrication system (Fig. 1.18) - combined, with oil supply to rubbing surfaces under pressure and splashing and automatic control of oil temperature by a thermal valve. Hydraulic valve lifters and chain tensioners are lubricated and operate under oil pressure.

The lubrication system includes: oil sump, oil pump with suction pipe and pressure reducing valve, oil pump drive, oil channels in the cylinder block, cylinder head and crankshaft, full-flow oil filter, rod indicator oil level, thermal valve, oil filler cap, oil drain plug, emergency oil pressure switch and oil cooler.

Oil circulation occurs as follows. Pump 1 sucks oil from crankcase 2 and brings it through the channel of the cylinder block to thermal valve 4.

At an oil pressure of 4.6 kgf / cm2 the pressure reducing valve 3 of the oil pump opens and the oil is bypassed back into the suction area of ​​the pump, thereby reducing the pressure increase in the lubrication system.

Maximum oil pressure in the lubrication system - 6.0 kgf/cm2 .

At oil pressure above 0.7-0.9 kgf / cm2 and temperatures above 79-83 ° C, the thermal valve begins to open a passage for the oil flow into the radiator, which is discharged

through fitting 9. The temperature of the full opening of the thermal valve channel is 104-114 ° С. The cooled oil from the radiator returns to the oil sump through hole 22. After the thermal valve, the oil enters the full-flow oil filter 6.

The purified oil from the filter enters the central oil line 5 of the cylinder block, from where it is supplied through channels 18 to the crankshaft main bearings, through channels 8 to the intermediate shaft bearings, through channel 7 to the upper bearing of the oil pump drive shaft and is also supplied to the hydraulic tensioner of the lower camshaft drive chains.

From the main bearings, oil is supplied through the internal channels 19 of the crankshaft 20 to the connecting rod bearings and from them through the channels 17 in the connecting rods is supplied to lubricate the piston pins. To cool the piston, oil is sprayed through the hole in the upper head of the connecting rod onto the piston crown.

From the upper bearing of the oil pump drive roller, oil is supplied through the transverse drillings and the inner cavity of the roller to lubricate the lower roller bearing and the bearing surface of the driven gear of the drive (see Fig. 1.21). The oil pump drive gears are lubricated by a jet of oil sprayed through a hole in the central oil line.

Rice. 1.18. Lubrication system diagram: 1 - oil pump; 2 - oil sump;

3 - oil pump pressure reducing valve; 4 - thermal valve; 5 - central oil line; 6 - oil filter; 7, 8, 10, 11, 12, 14, 17, 18, 19 - oil supply channels; 9 - fitting of the thermal valve for draining oil to the radiator; 13 - cover of the oil filler pipe; 15 - handle of the oil level indicator; 16 - emergency oil pressure alarm sensor; 20 - crankshaft; 21 - rod oil level indicator; 22 - hole for connecting the fitting of the hose for supplying oil from the radiator; 23 - oil drain plug

From the central oil line, oil through channel 10 of the cylinder block enters the cylinder head, where it is supplied through channels 12 to the camshaft bearings, through channels 14 to hydraulic pushers, through channel 11 to the hydraulic tensioner of the upper camshaft drive chain.

Escaping from the gaps and flowing into the oil sump at the front of the cylinder head, oil enters the chains, tensioner levers and camshaft drive sprockets.

At the rear of the cylinder head, oil flows into the oil sump through the head bore through a hole in the cylinder block lug.

Oil is poured into the engine through the oil filler pipe of the valve cover, closed by cover 13 with a sealing rubber gasket. The oil level is controlled by the marks printed on the oil level indicator 21: upper level - "MAX" and lower - "MIN". The oil is drained through an opening in the oil sump, closed drain plug 23 with gasket.

Oil cleaning is carried out by a mesh installed on the oil pump intake port, by filter elements of a full-flow oil filter, as well as by centrifugation in the crankshaft channels.

Oil pressure control is carried out according to the alarm oil pressure alarm ( control lamp on the instrument panel), the sensor 16 of which is installed in the cylinder head. The emergency oil pressure indicator lights up when the oil pressure drops below 40-80 kPa (0.4-0.8 kgf / cm2 ).

Oil pump (Fig. 1.19) - gear type, installed inside the oil sump, fastened with a gasket with two bolts to the cylinder block and a holder to the cover of the third main bearing.

The drive gear 1 is fixedly fixed on the shaft 3 with a pin, and the driven gear 5 rotates freely on the axis 4 pressed into the pump housing 2. At the upper end of roller 3, a hexagonal hole is made, into which the hexagonal shaft of the oil pump drive enters.

The centering of the drive shaft of the pump is carried out due to the fit of the cylindrical protrusion of the pump housing in the bore of the cylinder block.

The pump body is cast from an aluminum alloy, the baffle 6 and gears are made of cermet. A suction pipe 7 cast from aluminum alloy with a grid, in which a pressure reducing valve is installed, is attached to the body with three screws.

Rice. 1.19. Oil pump: 1 - drive gear; 2 - body; 3 - roller; 4 - axis; 5 - driven gear; 6 - partition; 7 - inlet pipe with a grid and a pressure reducing valve.

Pressure reducing valve (fig.1.20)- plunger type, located in the intake pipe of the oil pump. The valve plunger is made of steel, to increase the hardness and wear resistance of the outer working surface, it is subjected to nitrocarburizing.

The pressure reducing valve is adjusted at the factory by selecting washers 3 of a certain thickness. It is not recommended to change the valve setting in operation.

Rice. 1.20. Pressure reducing valve: 1 - plunger; 2 - spring; 3 - washer; 4 - cotter pin

Oil pump drive(Fig. 1.21) - carried out by a pair of helical gears from the intermediate shaft 1 of the camshaft drive.

On the intermediate shaft, with the help of a segment key 3, the drive gear 2 is installed and secured with a flange nut. The driven gear 7 is pressed onto the shaft 8, which rotates in the bores of the cylinder block. A steel bushing 6 is pressed into the upper part of the driven gear, having

internal hex hole. A hexagonal shaft 9 is inserted into the hole of the bushing, the lower end of which enters the hexagonal hole of the oil pump shaft.

From above, the oil pump drive is closed with a cover 4, fixed through a gasket 5 with four bolts. The driven gear during rotation of the upper end surface is pressed against the drive cover.

Rice. 1.21. Oil pump drive: 1 - intermediate shaft; 2 - drive gear;

3 - key; 4 - cover; 5 - gasket; 6 - bushing; 7 - driven gear; 8 - roller: 9 - hexagonal roller of the oil pump drive

The driving and driven helical gears are made of ductile iron and nitrided for improved wear resistance. The hexagonal shaft is made of alloy steel and carbon nitrided. drive roller

8 steel, with local hardening of supporting surfaces by high frequency currents.

Oil filter (Fig. 1.22). The engine is equipped with single-use full-flow oil filters of a non-separable design 2101С-1012005-NK-2 produced by "KOLAN", Ukraine, 406.1012005-01

f. Avtoagregat, Livny or 406.1012005-02 f. BIG-filter, St. Petersburg.

For installation on the engine, use only the specified oil filters, which provide high quality oil filtration.

Filters 2101C-1012005-NK-2 and 406.1012005-02 are equipped with a bypass valve filter element, which reduces the likelihood of untreated oil entering the lubrication system when starting a cold engine and limiting contamination of the main filter element.

Rice. 1.22. Oil filter: 1 - spring; 2 - body; 3 - filter element of the bypass valve; 4 - bypass valve; 5 - main filter element; 6 - anti-drainage valve; 7 - cover; 8 - gasket

Oil purification filters 2101C-1012005-NK-2 and 406.1012005-02 operate as follows: oil is supplied under pressure through the holes in the cover 7 into the cavity between the outer surface of the main filter element 5 and the housing 2, passes through the filter curtain element 5, is cleaned and enters across central hole covers 7 into the central oil line.

When the main filter element is extremely dirty or cold start, when the oil is very thick and hardly passes through the main filter element, the bypass valve 4 opens and the oil passes into the engine, being cleaned by the filter element 3 of the bypass valve.

The anti-drainage valve 6 prevents oil from flowing out of the filter when the car is parked and the subsequent "oil starvation" at start-up.

Filter 406.1012005-01 is designed similarly to the oil filters presented above, but does not contain the filter element 3 of the bypass valve.

The oil filter must be replaced at TO-1 (every 10,000 km) simultaneously with the oil change.

WARNING

The manufacturer installs a reduced volume oil filter on the engines, which must be replaced when carrying out Maintenance after running the first 1000 km on one of the above filters.

Thermal valve is designed to automatically control the oil supply to the oil cooler depending on the temperature of the oil and its

pressure. On the engine, a thermal valve is installed between the cylinder block and the oil filter.

The thermal valve consists of a housing 3, cast from an aluminum alloy, two valves: a safety valve, consisting of a ball 4 and a spring 5, and a bypass valve, consisting of a plunger 1 controlled by a thermal force sensor 2, and a spring 10; threaded plugs 7 and 8 with gaskets 6 and 9. The hose for supplying oil to the radiator is connected to fitting 11.

Rice. 1.23. Thermal valve: 1 - plunger; 2 - thermal force sensor; 3 - thermal valve body; 4 - ball; 5 - ball valve spring; 6 - gasket; 7, 8 - cork; 9 - gasket; 10 - plunger spring; 11 - fitting

From the oil pump, oil is supplied under pressure to cavity A of the thermal valve. At oil pressure above 0.7-0.9 kgf / cm2 the ball valve opens and oil enters channel B of the body of thermal valve B to plunger 1. When the oil temperature reaches 79-83 ° C, the piston of thermal force element 2, washed by the flow of hot oil, begins to move plunger 10, opening the way for the oil flow from channel B to the oil cooler .

The ball valve protects the rubbing parts of the engine from an excessive drop in oil pressure in the lubrication system.

Oil radiatorIt is an aluminum tube coil and serves for additional oil cooling. The oil cooler is connected to the engine oil line by a rubber hose through a thermal valve that operates automatically. Oil from the radiator is drained through a hose into the oil sump.

Control over the operation of the lubrication system in ZMZ 405, 406 and 409 engines is carried out using special oil pressure sensors. If they fail, the driver will not be able to respond in a timely manner to possible faults in the system, which will jeopardize the further performance of the entire power unit.

Pressure and emergency oil pressure sensors for engines ZMZ 405, 406, 409

In order to control the pressure in the lubrication system of ZMZ 405, 406 and 409 engines, two separate sensors are provided. One of them fixes the pressure value, and the second reacts to its critical drop.

Characteristics, design and principle of operation of the oil pressure sensor

The oil pressure sensor (DDM) is used to measure the lubricant pressure in the system. IN power plants ZMZ uses MM358 sensors with the following characteristics:

• working element - rheostat;
• rated current, A - 0.15;
• operating range, kgf / cm 2 - 0–6;
• resistance in the absence of pressure, Ohm - 159–173;

The design of the pressure sensor MM358 consists of:

• housings with fittings;
• membranes;
• pusher
• rheostat;
• rheostat drive elements.

The MM358 sensor works together with a pressure indicator located on the dashboard of the car. It has an electromechanical design that responds to changes in sensor resistance.

The principle of operation of the MM358 sensor is as follows: when the engine is not running, there is no pressure in the lubrication system. The resistance of the sensor, in accordance with its characteristics, is 159–173 ohms. When the power unit is started, the pressure increases, and the oil begins to act on the membrane, arching it inside the housing. Bending, it moves the transmission lever through the pusher, which, in turn, moves the sliders of the rheostat to the right, reducing the resistance of the sensor. The pointer reacts to this decrease by moving the arrow to the right.

Characteristics, design and principle of operation of the emergency oil pressure sensor

The emergency sensor is designed to inform the driver about the drop in oil pressure in the system to critical levels. IN power units ZMZ 405, 406 and 409 emergency oil pressure sensors of the MM111D type or similar, manufactured under catalog numbers 2602.3829, 4021.3829, 6012.3829. These are contact type devices, the principle of operation of which is based on the closing and opening of contacts.

Characteristics of the MM111D sensor:

• working element - diaphragm;
• rated voltage, V - 12;
• actuation at pressure, kgf / cm 2 - 0.4–0.8;
• the size of the landing thread, in inches - ¼.

Inside the body of the device is a spring-loaded diaphragm. A contact plate is attached to it, which is closed to the body (ground) of the sensor when not in use. During engine operation, pressurized lubricant enters the housing through a special hole and pushes the diaphragm away. The contacts are opened.

The emergency pressure sensor works in tandem with a signaling device, which is located on the instrument panel. It is made in the form of a red oil can. When we turn on the ignition without starting the engine, the oiler should be on. This indicates that voltage is applied to the sensor, and there is no pressure in the system. 3-5 seconds after starting the engine, the pressure in the system increases and reaches operating levels. The oil acts on the diaphragm, the contacts open, and the signaling device goes out.

Where are pressure sensors made?

Pressure sensors for ZMZ engines are produced both at the Ulyanovsk Automobile Plant and at other enterprises specializing in the manufacture of auto parts:

• "Autopribor";
• "Pekar";
• "EMI", etc.

Location in power units ZMZ 405, 406, 409

In ZMZ motors, the location of both sensors is identical. You will find them in the upper left of the cylinder head (when viewed from the passenger compartment) above exhaust manifold. And if the emergency sensor may not be immediately visible, then the oil pressure sensor is identified instantly by the barrel-shaped body.

Both sensors are screwed into one bifurcated fitting (tee), which is screwed into the cylinder head and connected to one of the oil channels of the lubrication system. Power wires are connected to the sensors.

How to check the oil pressure sensor

If you have any suspicions about the performance of the pressure sensor - do not be too lazy to check it. This can be done both at the service station and at home. But in the latter case, you will need to purchase a special pressure gauge. It costs about 300 rubles, but such a thing will come in handy in the future. In addition to it, you will also need a slotted screwdriver, a 22 key and electrical tape.

Checking order:

Video: checking the oil pressure in the system

Other malfunctions

However, a deviation in the pressure value can be associated with both wiring malfunctions and malfunctions of the pointer itself. Feel free to do additional diagnostics. Her order is as follows.

We turn on the ignition. The pointer arrow should deviate to the right, and then return to its original position. If the arrow does not deviate, unscrew the screw securing the sensor power wire with a slotted screwdriver, disconnect it and touch the ground. The arrow deviated - there is a short circuit in the sensor power wiring. If not, the problem should be sought in the pressure gauge.

Checking the emergency oil pressure sensor

To check the device you will need:

• slotted screwdriver;
• key for 22;
• ohmmeter (multimeter);
• tire pump with pressure gauge;
• a piece of hose with clamps of the appropriate diameter.

Checking order:

How to independently make a replacement in motors ZMZ 405, 406, 409

Instruments:

• slotted screwdriver;
• keys for 17 and 22;
• automotive sealant;
• dry rag;
• marker.

Replacement order:

1. Disconnect ground wire from battery.
2. Using a slotted screwdriver, unscrew the screw pressing the tip of the pressure sensor power wire. Disconnect the wire.
3. If you decide to replace both sensors, unscrew the fastening of the emergency sensor power wire with the same tool.
4. In order not to confuse the wires, we mark them with a marker.
5. Using a 17 key, unscrew the oil pressure sensor. We take it aside.
6. Using a 22 key, unscrew the emergency oil pressure sensor.
7. Gently wipe the sensor seats, remove the remnants of the old sealant.
8. Lubricate the sensor fittings with a thin layer of automotive sealant. Let it dry a little (30 s).
9. We screw in new sensors using keys 17 and 22.
10. We connect the power wires.
11. We connect the mass to the battery.
12. We check the operation of the sensors.

Video: replacing the oil pressure sensor on a Gazelle car

Do you decide on self-diagnosis and replacement of sensors, or resort to the help of specialists - it does not matter. The main thing is to be sure that the lubrication system is operating normally and have confirmation of this in the form of normal indicators of the relevant instruments, rather than relying on the fact that everything will work out.

In-line four-cylinder engine, equipped with a complex microprocessor
fuel injection and ignition control system (KMSUD).

Type of engine mod. 4062 on the left side:

1 - drain plug;
2 - oil crankcase;
3 - exhaust manifold;
4 – an arm of a support of the engine;
5 - coolant drain valve;
6 - water pump;
7 - sensor lamp overheating cooling
liquids;
8 - coolant temperature indicator sensor
liquids;
9 – tempera sensor;
10 - thermostat;
11 - emergency lamp sensor
oil pressure;
12 - pressure indicator sensor
oils;
13 - crankcase ventilation hose;
14 - oil level indicator (dipstick);
15 - ignition coil;
16 - phase sensor;
17 - heat-insulating screen
The cylinder block is cast in gray cast iron. Between the cylinders there are channels for
coolant. The cylinders are made without insert sleeves. At the bottom of the block
There are five crankshaft main bearings. Indigenous covers
bearings are made of ductile iron and are attached to the block with two bolts. Lids
bearings are bored together with the block, so they cannot be interchanged.
On all covers, except for the cover of the third bearing, their serial numbers are stamped.
The cover of the third bearing, together with the block, is machined at the ends for installation
thrust bearing half washers. The chain cover is bolted to the ends of the block and
gland holder with crankshaft cuffs. An oil sump is attached to the bottom of the block.
On top of the block is a cylinder head cast from aluminum
alloy. It has intake and exhaust valves. For each cylinder
Four valves are installed, two intake and two exhaust. intake valves
located with right side heads, and graduation - on the left. Valve drive
is carried out by two camshafts through hydraulic pushers.
The use of hydraulic pushers eliminates the need to adjust the gaps in the drive
valves, as they automatically compensate for the gap between the cams
camshafts and valve stems. Outside on the body of the hydraulic pusher
there is a groove and a hole for supplying oil inside the hydraulic pusher from the oil
highways.

Type of engine mod. 4062 on the right side:

1 - synchronization disk;
2 – speed and synchronization sensor;
3 - oil filter;
4 - starter;
5 - knock sensor;
6 - coolant drain pipe;
7 – air temperature sensor;
8 - inlet pipe;
9 - receiver;
10 - ignition coil;
11 - idle speed regulator;
12 - throttle;
13 - hydraulic chain tensioner;
14 - generator
The hydraulic pusher has a steel body, inside of which a guide is welded
sleeve. A compensator with a piston is installed in the bushing. The compensator is held in
bushing with a retaining ring. An expander is installed between the compensator and the piston.
spring. The piston rests against the bottom of the hydraulic pusher housing. Simultaneously
the spring compresses the body of the check ball valve. When the cam
camshaft does not press the hydraulic pusher, the spring presses through
piston body of the hydraulic pusher to the cylindrical part of the distribution cam
shaft, and the compensator - to the valve stem, while choosing the gaps in the drive
valves. The ball valve is open in this position and oil flows into
hydraulic pusher. As soon as the camshaft cam turns and presses on
pusher body, the body will move down and the ball valve will close. Butter,
located between the piston and the compensator, begins to work as a solid body.
The hydraulic pusher under the action of the camshaft cam moves down and opens the valve.
When the cam, turning, stops pressing on the body of the hydraulic pusher, it is under
the action of the spring moves upwards, opening the ball valve, and the entire cycle
repeats again.

Cross section of the engine mod. 4062

1 - oil crankcase;
2 – oil pump receiver;
3 - oil pump;
4 - oil pump drive;
5 - gear wheel of the intermediate shaft;
6 – block of cylinders;
7 - inlet pipe;
8 - receiver;
9 - intake camshaft
valves;
10 - inlet valve;
11 - valve cover;
12 - exhaust camshaft
valves;
13 - oil level indicator;
14 - hydraulic valve tappet;
15 - outer spring of the valve;
16 - valve guide sleeve;
17 - exhaust valve;
18 – a head of the block of cylinders;
19 - exhaust manifold;
20 - piston;
21 - piston pin;
22 - connecting rod;
23 - crankshaft;
24 - connecting rod cover;
25 – a cover of the radical bearing;
26 - drain plug;
27 - pusher body;
28 - guide sleeve;
29 - compensator housing;
30 - retaining ring;
31 - compensator piston;
32 - ball valve;
33 - ball valve spring;
34 - body of the ball valve;
35 - expanding spring
Saddles and guide bushings are installed in the head of the block with a large interference fit
valves. In the lower part of the block head, combustion chambers are made, in the upper part -
camshaft bearings are located. Mounted on aluminum poles
covers. The front cover is common to the intake and exhaust supports.
camshafts. This cover has plastic stoppers.
flanges that fit into the grooves on the camshaft journals. Lids
are bored together with the head of the block, so they cannot be interchanged. On the
all covers, except for the front, are embossed with serial numbers.

Camshaft cover installation diagram

The camshafts are cast iron. Inlet and outlet cam profiles
shafts are the same. The cams are displaced by 1.0 mm relative to the axis of the hydraulic pushers, which
makes them rotate when the engine is running. This reduces surface wear.
hydraulic pusher and makes it uniform. The top of the head of the block is closed with a lid,
cast from aluminum alloy. The pistons are also cast aluminum alloy. On the
The bottom of the piston has four recesses for the valves, which prevent
piston strikes on valves in violation of the valve timing. For the correct
installation of the piston in the cylinder on the side wall at the boss under the piston pin is cast
inscription: "Before". The piston is installed in the cylinder so that this inscription is
facing the front of the engine.
Each piston has two compression rings and one oil scraper ring.
The compression rings are cast iron. Barrel-shaped working surface of the upper
rings are covered with a layer of porous chromium, which improves the running-in of the ring. working
the surface of the lower ring is covered with a layer of tin. On the inner surface of the bottom
ring has a groove. The ring must be installed on the piston with this groove
up to the bottom of the piston. Oil scraper ring consists of three elements: two
steel discs and expander. The piston is attached to the connecting rod with a piston
finger "floating type", i.e. the pin is not fixed in either the piston or the connecting rod. From
movement, the finger is held by two spring retaining rings, which
installed in the grooves of the piston bosses. Forged steel connecting rods, with rod
double section. A bronze bushing is pressed into the upper head of the connecting rod.
The lower head of the connecting rod with a cover, which is fastened with two bolts. Connecting rod nuts
bolts have a self-locking thread and therefore do not additionally lock.
The connecting rod caps are machined with the connecting rod and therefore cannot be
move from one rod to another. Numbers stamped on connecting rods and caps
cylinders. For cooling the piston crown with oil in the connecting rod and top head
holes are made. The mass of pistons assembled with connecting rods should not differ
more than 10 g for different cylinders. In the lower head of the connecting rod is installed
thin-walled connecting rod bearings. Crankshaft cast from ductile iron.
The shaft has eight counterweights. It is kept from axial movement by thrust
half washers mounted on the middle neck. To the rear end of the crankshaft
flywheel attached. A spacer sleeve and a bearing are inserted into the flywheel bore
gearbox input shaft.
Cylinder numbers are stamped on the connecting rods and connecting rod caps. For bottom cooling
piston oil holes are made in the connecting rod rod and the upper head. Weight
pistons assembled with connecting rods should not differ by more than 10 g for different
cylinders. Thin-walled connecting rods are installed in the lower head of the connecting rod.
liners. The crankshaft is cast from ductile iron. The shaft has eight
counterweights. It is kept from axial movement by persistent half washers,
mounted on the middle neck. Attached to the rear end of the crankshaft
flywheel. A spacer sleeve and primary bearing are inserted into the flywheel bore.
gearbox shaft.