Let's consider the malfunctions that may occur during engine operation:

  • - The crankshaft is not turned by the starter;
  • - Strong noise during starter operation;
  • - The crankshaft is turned by the starter, but the engine does not start;
  • - The engine is unstable or stalls at idle;
  • - The engine does not develop full power, the car does not have sufficient throttle response. Jerks and dips when driving a car;
  • - Pops in the intake pipe;
  • - Shots in the silencer;
  • - Increased fuel consumption;
  • - Increased oil consumption (more than 500 g per 1000 km);
  • - Detonation (high-pitched metallic knocks that occur, as a rule, when the engine is running under load, especially at low speeds, for example, “pull-in” acceleration, etc. and disappear when the load is reduced);
  • - Insufficient oil pressure (low oil pressure indicator is on);
  • - The engine is overheating (the arrow of the coolant temperature gauge is in the red zone of the scale);
  • - The electric fan of the engine cooling system is constantly running (even on a cold engine);
  • - The engine takes a long time to warm up to operating temperature;
  • - Coolant level drop in the expansion tank;
  • - Extraneous noises and knocks in the engine;
  • - Strong engine vibration;
  • - Increased content of harmful substances in exhaust gases;
  • - Engine control system malfunction indicator engine malfunction lights up when the engine is running.

Possible faults - diagnostics - troubleshooting

The crankshaft does not turn with the starter:

-The battery is low. The voltage at the terminals of the battery when consumers are off is below 12V. When the starter is turned on, a crackling noise may be heard from under the hood.

Charge the battery; if it does not charge - replace

- Decreased battery capacity. The voltage at the battery terminals with the consumers turned off is more than 12 V, but when the starter is turned on, crackling can be heard from under the hood.

Charge the battery with a low current (no more than 1 A); if the capacity is still insufficient, replace it.

- Oxidation of the battery terminals, loose fit. When the starter is turned on, the voltage in the on-board network drops much more than at the battery terminals. When the starter is turned on, a crackling noise may be heard from under the hood.

Crimp the terminals, clean the contacts, lubricate them with petroleum jelly.

- Engine jam

Check the free rotation of the crankshaft, alternator, coolant pump

Repair the engine, generator, replace the coolant pump

- Damaged starter clutch gear or flywheel teeth

Inspection

Replace starter or flywheel

- The starter traction relay control circuit is faulty: the wires are damaged, the tips are oxidized or loose, the contacts "30" and "50" of the ignition switch do not close

When the key is turned to the "starter" position, the traction relay does not work (there is no click under the hood).

Check if +12 V is supplied to the control contact of the traction relay

Strip, crimp the wire lugs; replace the faulty ignition switch or its contact part

- The contacts of the traction relay or wires are oxidized, poor ground contact

When the starter is engaged, a click is heard under the hood, but the starter armature does not rotate.

Check the resistance of the "battery - starter" circuit with an ohmmeter, including the "ground" wire. If the circuits are OK, remove the starter and check the operation of its relay

Tighten the wire ends, crimp the terminals Replace the defective relay

  • - Commutator burning, brushes stuck or worn out
  • - Open or short circuit in the armature winding
  • - The starter armature does not rotate or rotates slowly (make sure the traction relay is working beforehand).

It is possible to supply power to the starter, bypassing the traction relay. Carefully! Avoid sparks near the battery!

On the removed starter, check the brush pressure against the commutator, their residual height, commutator wear

- The starter armature does not rotate or rotates slowly.

First make sure that the traction relay is working. You can supply power to the starter, bypassing the traction relay. Carefully! Avoid sparks near the battery!

Checked with an ohmmeter or darkening of the insulation

Scrape the collector with fine-grained glass wool, rinse with unleaded gasoline, ensure that the brushes move freely in the sockets. If the manifold is very worn, replace the starter

Replace the starter

  • - Open or short circuit in the holding winding of the starter relay
  • - Freewheel slip
  • - The ring gear rotates on the flywheel. When the starter is turned on, a crack is heard from under the hood. Battery voltage is within normal limits. The relay is checked with an ohmmeter or by its excessive heating
  • - When the starter is turned on, the armature rotates, the flywheel is stationary
  • - When the starter is turned on, the ring gear rotates, the flywheel is stationary. Screeching, howling from the clutch housing

Replace starter solenoid

Replace clutch or starter

Replace flywheel

Strong noise during starter operation:

- The fastening of the starter pole has loosened (anchor touches it)

Disassemble the starter, inspect, check the alignment of the poles and the gap between them and the anchor

Tighten the poles or replace the starter

- The ring gear rotates on the flywheel

When the starter is turned on, the ring gear rotates, the flywheel is stationary. Squealing from the clutch housing

Replace flywheel

- The teeth of the starter drive gear or - more often - the flywheel ring are worn out

Inspection

Replace starter or flywheel

  • - The gear does not disengage from the flywheel: the drive lever is stuck;
  • - weakening or breakage of the freewheel spring or starter traction relay;
  • - jamming of the clutch on the splines of the armature shaft or the core of the traction relay;
  • - malfunction of the ignition switch (contacts "30" and "50" do not open)

Checking the removed starter, inspection after disassembly. The operation of the ignition switch can be checked with an ohmmeter or visually by removing its contact part

Replace the starter traction relay or starter assembly, ignition switch contact group or switch assembly

The crankshaft is turned by the starter, but the engine does not start:

There is no fuel in the tank. According to the fuel gauge and control lamp - Add fuel

Reduced battery capacity, loose fit. The voltage at the terminals of the battery when consumers are off is below 12V. When you turn on the starter, a crack may be heard from under the hood

Charge the battery, if it does not charge, replace it.

- Malfunction in the low voltage circuit

Check with an ohmmeter the circuit from the battery to the ignition coil (through the ignition switch) and then to the switch

Clean oxidized terminals, tighten loose wire fasteners, replace damaged wires, ignition switch or its contact part

- Faulty Hall sensor

Determined by a voltmeter or by replacing the sensor with a known good one

Replace the defective sensor

- Faulty circuit "switch - Hall sensor"

Check with an ohmmeter

Recruit oxidized tips, tighten loose wire fasteners, replace damaged wires.

- Faulty switch

Replace the switch with a working one

Replace defective switch

- Damage to the insulation of high-voltage devices and circuits

Having securely fastened the end of the high-voltage wire at a distance of 8-10 mm from the "mass" of the car, scroll the engine with a starter (do not touch the high-voltage circuits!).

A spark should jump regularly between the wire and ground (use only good I/O wires for testing).

If there is no spark at the output of the ignition coil, the coil is faulty, if at the output / outputs of the ignition distributor, the rotor or distributor cap is faulty.

Rotor or lid burnouts are determined visually. The health of the rotor resistor (1 kOhm) is checked with an ohmmeter.

To check, replace the wires and the ignition module with good ones

Replace defective ignition coil/module. Replace damaged high-voltage wires.

In severe operating conditions (salt on the roads, frost alternating with thaws), it is advisable to replace the wires every 3-5 years.

Clean the cover and the distributor rotor from dirt and moisture, replace the burned-out resistor of the rotor, if you suspect a breakdown of the insulation (burnouts, cracks) of the rotor and the distributor cover - replace them

- High voltage wires are connected to the distributor/ignition module in the wrong order

Inspection

Connect the wires according to the firing order of the cylinders

- The gap between the electrodes of the candles does not correspond to the norm

A gap of 0.7-0.8 mm or 1.0-1.1 mm is checked with a round feeler gauge

Bending the side electrode, set the desired gap or replace the candles

- Defective candles

Candles are checked on a special stand

Replace spark plugs

- Faulty ignition timing

Adjust ignition timing

- Camshaft phases are knocked down

Check the alignment of the marks on the crankshaft and camshaft

Set the correct relative position of the shafts (by marks)

- Faulty blok engine control, its circuit or crankshaft position sensor (less often - coolant temperature sensor)

The CHECK ENGINE lamp lights up.

Check if +12 V is supplied to the control unit (see diagram), the crankshaft position sensor circuit, the sensor itself is not damaged and the gap between it and the crankshaft ring gear (1 ± 0.2 mm). The resistance of a good sensor is 500-700 Ohm.

- In the event of a break in the temperature sensor or its circuit, the electric fan of the cooling system operates continuously

Replace the faulty unit, sensors, wires

- The control pulse from the crankshaft position sensor does not arrive in time due to the delamination of the crankshaft damper * (the gear has moved relative to the pulley)

Inspection

Replace the damper (you can install a cast iron pulley)

- Faulty idle speed controller or its electrical circuit

The CHECK ENGINE lamp lights up. When starting the engine, slightly press the "gas", slightly opening the throttle. If the engine starts, but stalls when the pedal is released, the regulator is faulty

Replace defective regulator

- Injection system fuse or fuse blown

Inspection: check the fusible link - a piece of black wire, a non-switchable power fuse and a main relay fuse

Check the circuits and devices of the injection system, eliminate the cause of the burnout, replace the fuse or fuse

- Starting the engine blocks the immobilizer

The red LED continues to flash, indicating armed mode

The immobilizer, even in the locked state, allows at least one start of the engine (for more details, see the description of the immobilizer operation in the vehicle operation manual). You can also start the engine by installing a new control unit

- Fuel filters are clogged, water in the power system is frozen, hoses are pinched, fuel lines are deformed, the fuel pump is faulty

When the engine is cranked with a starter, there is no smell of gasoline from the exhaust pipe. There is no gasoline in the carburetor float chamber - when you press the "gas" from the accelerator pump sprayer, there is no fuel jet.

The presence of gasoline (under pressure) in the fuel rail can be checked by briefly pressing the spool of the fitting at the end of the rail (remember that gasoline is flammable!)

In winter, drive the car into a warm garage, blow (with a tire pump) the power supply system from the fuel pump to the gas tank and, replace the fuel pump or its diaphragms, defective hoses and pipes

- Bad contact in the power supply circuit of the fuel pump (including the "ground" wires) or its relay is faulty

Checked with an ohmmeter

Clean the contacts, crimp the terminals, replace the faulty relay, wires

- The fuel pump does not create the necessary pressure in the system

Check the pressure at the outlet of the fuel pump (not less than 3.5 bar (350kPa)), make sure the strainer of the fuel pump is clean

Clean the fuel gauge. Replace the fuel pump that does not provide the required pressure in the system

- Faulty injectors or their circuits

The CHECK ENGINE lamp lights up.

Check the injector windings and their circuits with an ohmmeter (no open circuit or short circuit)

Replace defective injectors, ensure contact in electrical circuits

- The carburetor solenoid valve is faulty or no voltage is applied to it when the ignition is turned on

Replace the faulty valve, EPHX control unit, ensure contact in the electrical circuits.

Do not apply too much force when tightening the valve (risk of deformation!)

- The carburetor starter or its drive is faulty or not adjusted

Adjust the starting device, replace the failed parts

- Jets and carburetor channels are clogged. Loosely wrapped jets, solenoid valve

Inspect, blow channels and jets

Rinse with gasoline or acetone and blow through the jets, if heavily soiled, clean them with a fishing line or a softwood needle. Tighten the jets tightly (do not damage the threads and the jet!)

- Intake of extraneous air into the intake manifold

Inspect the joints, check the fit of the hoses, fittings, tightness of the clamps. At the time of starting, turn off the vacuum brake booster by pinching the corresponding hose

Torn gaskets, parts with deformed flanges, defective vacuum booster, replace

- Excessive fuel level in the carburetor float chamber

There is a strong smell of gasoline from the exhaust pipe, a cold engine starts better than a hot one.

Remove the top cover of the carburetor, check the integrity of the floats, the ease of movement and the absence of touching the walls of the float chamber.

Checking the tightness of the needle valve: turn the carburetor cap upside down and pump gasoline with the fuel pump lever. The slightest leak of gasoline fromd needle or valve base is not allowed

Replace needle valve, adjust float chamber fuel level

- Insufficient fuel level in the carburetor float chamber

Adjust fuel level

- Re-enriched mixture due to gasoline leaking into the crankcase through a torn fuel pump diaphragm. The oil on the dipstick smells like gasoline, the low oil pressure lamp may light up at idle engine speed

Replace the fuel pump or diaphragm, if there is a lot of gasoline in the oil, then oil

- The fuel pressure regulator is faulty (the drain channel is constantly open)

Check the pressure in the fuel rail with a pressure gauge (2.5 -3.5 bar)

Replace the defective regulator

- Faulty mass air flow sensor. The "CHECK ENGINE" lamp lights up

The fault is typical for frequency-type sensors

Replace the defective sensor.

You can get to the place of repair by disconnecting the connector from the sensor (in this case, the engine speed will increase to approximately 2000 min

In cold weather, the engine stops shortly after the start of movement, but after a short stop it starts again:

- An ice plug has formed in the carburetor diffuser (the thermal force element does not work or the heated air hose is not connected to the outlet on the exhaust manifold)

Inspection

Clamp the hose to the heated air intake. Replace defective thermal element

In hot weather, the engine spontaneously stops and starts with difficulty:

- Vapor lock in the power system. The fuel drain line to the tank does not work - tubes, hoses are clogged or pinched, the check valve is faulty

Inspect the fuel lines, blow out the line with compressed air

Remove kinks in hoses, replace deformed tubes, defective check valve

The engine does not develop full power and does not have sufficient throttle response. Jerks and dips when driving a car:

- The engine is not warmed up. By temperature indicator

Warm up the engine to operating temperature

- The starting device or its drive is faulty or not adjusted

Adjust the starting device, if necessary, replace the defective elements

- Insufficient fuel level in the carburetor float chamber. Clogged jets and carburetor channels. Loosely wrapped jets

When closing the air damper, jerks and dips decrease or disappear completely.

Inspect, blow channels and jets

Adjust the fuel level. Rinse with gasoline or acetone and blow through the jets, if heavily soiled, clean them with a fishing line or softwood needle. Tighten the jets tightly (do not damage the threads of the jet)

- Intake of extraneous air into the intake manifold

Inspect the joints, check the fit of the hoses, fittings, tightness of the clamps.

For a short time, disconnect the vacuum brake booster by pinching the corresponding hose (Caution! The effort on the brake pedal will increase significantly!)

Torn gaskets, parts with deformed flanges, defective vacuum booster, replace

- Excessive fuel level in the carburetor float chamber

There is a strong smell of gasoline from the exhaust pipe, a cold engine starts better than a hot one.

Remove the top cover of the carburetor, check the integrity of the floats, the ease of movement and the absence of touching the walls of the float chamber.

Testing the needle valve for leaks: turn the carburetor cap upside down and pump gasoline with the fuel pump lever. The slightest leak of gasoline from under the needle or valve base is unacceptable

Replace needle valve, adjust float chamber fuel level

- Re-enriched mixture due to gasoline leaking into the engine crankcase through a torn fuel pump diaphragm

The oil on the dipstick smells like gasoline, the low oil pressure lamp may light up when the engine is idling

Replace the fuel pump or its diaphragm, if there is a lot of gasoline in the oil, then oil

- Incomplete throttle opening

Identified visually with the engine stopped

Adjust the throttle actuator

- Low compression in the cylinders: wear or damage to valves, seats, wear, sticking or breakage of piston rings

Warm the engine up to operating temperature and remove the spark plugs.

Fully press the gas pedal and, inserting a compression gauge into the spark plug holes, scroll the crankshaft with a starter (work together, while shorting the high-voltage wire of the ignition coil to ground, turn off the engine control system by removing the appropriate fuse.

Repeat the measurements, pouring 10-15 cm3 of engine oil into the cylinders through the spark plug holes. In those cylinders where the compression has increased by more than 2 kgf / cm2 (0.2 MPa), the rings may be very worn out are broken or buried.

If the compression remains below 10 kgf / cm2 (1 MPa), wear or damage to the valves or their seats is possible

Replace rings, pistons.

Repair the cylinders.

Lap the valves to the seats, if necessary, replace the valves, their guide bushings, grind the seats

- The control pulse from the crankshaft position sensor does not arrive in time due to the delamination of the crankshaft damper * (the gear has moved relative to the pulley)

Inspection of the (preferably removed) damper

Replace the damper (you can install a cast iron pulley)

- The gap between the electrodes of the candles does not correspond to the norm

Gap 07-08mm or 1.0-1.1mm is checked with a round feeler gauge

Bending the side electrode, set the desired gap or replace the candles

- Strong carbon deposits on the electrodes of spark plugs, ingress of carbon particles and the gap between the electrodes

Inspection

Clean the spark plugs with compressed air or mechanically (do not damage the insulator!), make sure they work <0> (the absence of external damage and sparking between the electrodes on an inverted candle does not allow us to conclude that it is working).

Identify and eliminate the cause of increased carbon formation in the combustion chamber, if necessary, replace the candles

- Wear, damage to the contact carbon in the cover of the ignition distributor. Coal spring weakened

Inspection

Replace the distributor cap or ember with spring

- The resistor in the rotor of the ignition distributor burned out

Checked with an ohmmeter (1 kOhm)

Replace resistor or rotor

- Insulation burnout of high-voltage circuits

Checked with an ohmmeter and visually (black cracks, insulation melting). Replace high-voltage wires for testing with serviceable ones

Replace the faulty ignition distributor cap, rotor (runner), ignition coil module, high voltage wires

- Faulty switch

Replace the switch with a working one

Replace defective switch

- Weakening or breakage of the springs of the weights of the centrifugal machine of the ignition distributor, the damper rings of the weights are lost, the weights sticking and the fuzzy operation of the vacuum ignition advance machine: when the vacuum is removed, the plate does not return to its original position

Visually or on a special stand

Replace the ignition distributor

- Fuzzy operation of the vacuum ignition advance machine: when the vacuum is removed, the plate does not return to its original position

Inspection.

The characteristic of the vacuum regulator is taken on a special stand

Remove the jam, replace the faulty vacuum machine or ignition distributor assembly

- There is little fuel in the tank

According to the fuel gauge and control lamp

Add fuel

- Clogged fuel filters, frozen water in the power system, pinched hoses, deformed fuel lines

Inspect fuel lines, replace filters. The pressure in the fuel rail can be checked with a pressure gauge

In winter, drive the car into a warm garage, blow (with a tire pump) the power supply system from the fuel pump to the gas tank and replace defective hoses, tubes, filters

- The fuel pump does not create the necessary pressure in the system

Replace the fuel pump or its diaphragms

-The fuel pump does not create the necessary pressure in the system

Check the pressure at the outlet of the fuel pump (at least 3.5 bar (3.5 kPa)), make sure the strainer of the fuel pump is clean

Clean the fuel gauge. Replace the fuel pump that does not provide the required pressure in the system

- Bad contact in the fuel pump power supply circuit (including ground wires) or its relay is faulty

Checked with an ohmmeter

Clean the contacts, crimp the terminals, replace the faulty relay, wires

- Faulty injectors or their circuits

The CHECK ENGINE lamp is on.

Check the injector windings and their circuits with an ohmmeter (no open circuit or short circuit)

Replace defective injectors, ensure contact in electrical circuits

- Faulty crankshaft position sensor or its circuit

The CHECK ENGINE lamp is on.

Check the sensor with an ohmmeter (resistance 500-700 ohms) or replace it with a known good one.

Clean the sensor rod from metal dust, check the gap between it and the crankshaft ring gear (1 ± 0.2 mm)

Restore the contact in the electrical circuits, replace the faulty sensor

- Faulty injection coolant temperature sensor or its circuit

The CHECK ENGINE lamp is on.

Check the sensor resistance with an ohmmeter at different temperatures

In the event of an open in the circuit or sensor, the electric fan of the cooling system runs continuously

Restore the contact in the electrical circuits, replace the faulty sensor

- Faulty throttle position sensor or echain

The CHECK ENGINE lamp is on.

In the event of an open circuit or sensor, the engine speed will not drop below 1500 rpm. The car accelerates well when you press the gas pedal

Restore the contact in the electrical circuits, replace the faulty sensor

- Faulty knock sensor

When there is a break in the electrical circuit, the "CHECK ENGINE" lamp lights up.

There is no detonation in any modes when using gasoline recommended by the manufacturer). The dynamics of the car is getting worse

Restore the contact in the electrical circuits, replace the faulty sensor

- The oxygen sensor is faulty *: the sensitive element is poisoned or destroyed, the hole for air suction is clogged, the heating coil is burned out, the electrical circuits are faulty

The CHECK ENGINE lamp is on.

You can roughly evaluate the operation of the sensor with an autotester: the integrity of the heating coil is checked with an ohmmeter, the output voltage is checked with a voltmeter (you should connect the voltmeter without breaking the circuit, for example, by piercing the wires with thin needles). See also "Engine management system
VAZ-2111". Check if the air intake hole is blocked (anticorrosive, dirt, etc.)

Repair damaged electrical circuits, clean the air intake hole. Replace defective sensor

- Leakage of the exhaust system (area to the oxygen sensor)

The CHECK ENGINE lamp may be on.

Inspection at medium engine speeds

Replace defective manifold gasket, tighten seals

- Faulty engine control unit or its circuit

The CHECK ENGINE lamp may be on.

Inspection at medium engine speeds

Check if +12 V is supplied to the control unit (see diagram), to check the unit, replace it with a working one

Replace the failed unit

- Faulty fuel pressure regulator

Check the pressure in the fuel rail with a pressure gauge (2.5-3.5 bar (250-350 kPa))

Replace the defective regulator

- Valve clearances not adjusted

Checked with a set of probes

Adjust gaps

- Strong wear of the camshaft lobes

Inspection after partial engine disassembly

Replace worn camshaft

- Settlement or breakage of valve springs

Inspection, measurement of the length of the springs in the free state and under load

Replace weak or broken springs

Slamming in the intake manifold:

- Incorrect ignition timing

Adjust ignition timing

- Faulty switch

Replace the switch with a working one

Replace defective switch

- Camshaft phases are knocked down

Check the alignment of the marks on the crankshaft and camshaft

Set the correct relative position of the shafts using the marks

- The control pulse from the crankshaft position sensor does not arrive in time due to the delamination of the crankshaft damper * (the gear has moved relative to the pulley)

Inspection of the (preferably removed) damper

Replace the damper (you can install a cast iron pulley)

High idle:

- Incorrect ignition timing

Adjust ignition timing

- Faulty switch

Replace the switch with a working one

replace defective switch

- Camshaft phases are knocked down

Check if the marks on the crankshaft and camshaft match

set the correct position of the shafts

- Insulation burnout of high-voltage circuits

Checked with an ohmmeter and visually (black cracks, insulation melting). Replace high-voltage wires for testing with serviceable ones

Replace faulty distributor cap/module, high voltage wires

Pops in the intake manifold after engine operation at power modes:

- Candles with the wrong glow value are used

Inspection

Use spark plugs recommended by the manufacturer

Increased fuel consumption:

- Leakage of the power supply system

Smell of gasoline drips

Tighten the hose clamps, threaded connections. Check fit of fittings; when the fit is loose, replace the corresponding nodes

- Re-enriched mixture due to gasoline leaking into the engine crankcase through a torn fuel pump diaphragm

The oil on the dipstick smells like gasoline, the low oil pressure lamp may light up when the engine is idling

Replace the fuel pump or its diaphragm, if there is a lot of gasoline in the oil, then oil

- Increased resistance to vehicle movement

The run-off of a warm car (after a run of at least 20 km) from a speed of 50 km / h must be at least 500 m

Check and adjust tire pressure, front wheel alignment, brake system

- The starting device or its drive is faulty or not adjusted

Adjust the trigger, come out Replace any broken parts

- Excessive fuel level in the carburetor float chamber

There is a strong smell of gasoline from the exhaust pipe, a cold engine starts better; than hot.

Remove the top cover of the carburetor, check the integrity of the floats, the ease of movement and the absence of touching the walls of the float chamber.

Testing the needle valve for leaks: turn the carburetor cap upside down and pump gasoline with the fuel pump lever. The slightest leak of gasoline from under the needle or valve base is unacceptable

Replace needle valve, adjust float chamber fuel level

- Jets and carburetor channels are clogged. Loosely wrapped jets, solenoid valve. Accelerator pump check valve leaking

Inspect, blow channels and jets

Rinse with gasoline or acetone and blow through the jets, if heavily soiled, clean them with a fishing line or a softwood needle. Tighten the jets tightly (do not damage the threads and the jet!). Replace damaged parts

- Incorrect ignition timing

Adjust ignition timing

- Faulty switch

Replace the switch with a working one

Replace defective switch

- The control pulse from the crankshaft position sensor does not arrive in time due to the delamination of the crankshaft damper * (the gear has moved relative to the pulley)

Inspection (better than a removed damper)

Replace damper

The engine is overheating (the needle of the coolant temperature gauge is in the red zone):

- Faulty sensor or temperature indicator

Check the pointer and sensor with an autotester

Faulty sensor, replace pointer

- Faulty thermostat

Replace defective thermostat

- Insufficient amount of coolant

The fluid level is below the "MIN" mark on the expansion tank

Fix leaks, add coolant

- Vapor locks in the cooling system due to leakage of the expansion tank plug

Apply soap suds to the reservoir cap, stop the engine and squeeze the cooling system hoses with your hands. Air must not escape from the cork

replace the plug or tank

- Radiator cells are dirty

Inspection

Rinse the radiator with a pressurized water jet

- Faulty coolant pump

Remove the pump

Replace pump

- The electric fan of the cooling system does not turn on

Short the radiator thermal switch contacts together. If the fan is running, the thermal switch is faulty, if not, the electrical circuits or the fan motor (checked with an ohmmeter).

Check if +12V is being supplied to the control contact of the blower relay. If yes, then the relay or fan motor is faulty, if not, the injection control unit or its circuits (in this case, as a rule, the “CHECK ENGINE” lamp is on)

Restore contact in electrical circuits. Faulty thermal switch, relay, electric motor, control unit, replace

- Inadmissibly low octane number of gasoline

Fill the car with the fuel recommended by the manufacturer.

- A lot of carbon deposits in the combustion chamber, on the bottoms of the pistons, valve plates

Inspection after removal of the engine head

Remove the cause of carbon formation. See "Increased Fuel Consumption", "Increased Oil Consumption". Use oils of the recommended viscosity and, if possible, with a low ash content

- Incorrect ignition timing

Adjust ignition timing

- Faulty switch

Replace the switch with a working one

Replace defective switch

The electric fan of the engine cooling system is constantly running (even on a cold engine):

- An open in the injection coolant temperature sensor or in its circuits

The "CHECK ENGINE" lamp is on

The sensor and circuits are checked with an ohmmeter

Replace defective sensor

- The contacts of the relay for turning on the electric fan do not open

Check by tester

Replace defective relay

- The control unit of the injection system or its circuit is faulty

The "CHECK ENGINE" lamp of the injection theme or its circuit may be on

Check the unit at the service station or replace it with a serviceable one

Replace the failed unit

- The contacts of the radiator thermal switch do not open

When connecting the terminals from the terminals of the thermal switch, the electric fan stops working

Replace thermal switch

The engine takes a long time to warm up to operating temperature:

- Faulty thermostat

Replace defective thermostat

- Low air temperature (below - 15° С)

Insulate the engine: install thermal and sound insulation of the hood, shields in front of the radiator (do not block the entire area of ​​the radiator in the fan impeller area!)

Extraneous noises and knocks in the engine gatelet:

- Clearances in the valve mechanism do not correspond to the norm

Measure the gaps with a feeler gauge

Adjust gaps

- Knock crankshaft and camshaft, connecting rod bearings, pistons, piston pins, play or seizing in the bearings of the coolant pump

Repair or replacement of parts

Strong engine vibration:

- Irregularity of compression over the cylinders more than 2 kgf / cm2 (0.2 MPa): wear or damage to valves, seats, wear, sticking or breakage of piston rings

Warm the engine up to operating temperature and remove the spark plugs. Fully press the “gas” pedal and, inserting a compression gauge into the spark plug holes, turn the crankshaft with a starter (work together).

In this case, the high-voltage wire of the ignition coil should be shorted to ground and the engine control system should be turned off by removing the appropriate fuse. Repeat the measurements, pouring 10-15 cm3 of engine oil into the cylinders through the spark plug holes.

In those cylinders where the compression has increased by more than 2 kgf / cm2 (0.2 MPa), the rings are probably badly worn, broken or stuck.

If the compression remains below 10 kgf / cm2 (1 MPa), wear or damage to the valves or their seats is possible

Replace rings, pistons.

Repair the cylinders. Lap the valves to the seats, if necessary, replace the valves, their guide bushings, grind the seats

- Insulation burnout of high-voltage circuits

Checked with an ohmmeter and visually (black cracks, insulation melting). Replace high-voltage wires for testing with serviceable ones

Replace defective ignition distributor cap, rotor (runner), ignition coil/module, high voltage wires

- High voltage wires are connected to the distributor or ignition module in the wrong order

Inspection

Connect the wires according to the firing order of the cylinders

- Defective candles

Candles are checked on a special stand. (The absence of external damage and sparking between the electrodes on an inverted candle does not allow us to conclude that it is working)

Replace spark plugs

new

The lubrication system diagram is shown in Fig. 1. Oil pressure in the lubrication system of a warm engine at low crankshaft speed 550–650 min -1

In the article we will consider possible malfunctions of the front axle of the UAZ-3151