If noticeable noises and knocks appear in a running engine, you should find out the cause of their occurrence and do not operate the engine until the malfunction is eliminated

In a cold engine, after starting, knocking noises from valve lifters and hydraulic tensioners may occur.

As the engine warms up to operating temperature, but no more than after 30 minutes, the knocking should disappear.

Do not allow the engine to overheat.

If the coolant overheating indicator lights up, you should immediately stop the engine, identify and eliminate the cause of overheating.

It is not allowed to operate the engine with the emergency oil pressure warning light on.

This will lead to scuffing of the crankshaft and camshaft bearings and failure of the gas distribution mechanism.

The indicator light may come on when the engine is running at minimum speed in idle mode and during sudden braking.

It is not allowed to operate the engine with the diagnostic lamp on. A constant light on the lamp indicates a malfunction in the engine control system.

It is necessary to diagnose the system and eliminate the malfunction as soon as possible.

Probable cause - Remedy

The engine does not start:

  • a) air leakage into the intake manifold, bypassing the mass air flow sensor - Eliminate leakage
  • b) violation of the timing phase setting - correct the timing phase setting
  • - Gasoline supply failure
  • a) the electric fuel pump (EFP) does not work - Check the integrity of the fuse. Check the serviceability and reliability of the EBN connectors, the starting relay (PR) and the EBN relay. When you turn on the ignition, you should hear a characteristic sound for 2-3 seconds of EBN operation.
  • b) the fuel pressure regulator is faulty - replace the regulator
  • c) the fine fuel filter is clogged - replace the filter
  • d) the fuel line is clogged or the water in the fuel line is frozen - blow out the fuel line with compressed air
  • e) lack of fuel in the tank - add fuel to the tank
  • - Malfunctions in KMSUD
  • a) the gap between the spark plug electrodes does not correspond to the norm - check the gap with a round feeler gauge and adjust
  • b) spark plugs are faulty (shorting of the central electrode with carbon deposits on the insulator cone) - replace the faulty spark plugs. When shunting with carbon deposits, eliminate the cause of the malfunction
  • c) there is no signal from the synchronization sensor (DSSV) - check the reliability of the connector and the serviceability of the sensor
  • d) there is no contact in the electrical circuit of the ignition coils, control unit - check the serviceability and reliability of the connectors. After each check operation of the connector, perform a test run of the engine
  • e) control unit is faulty - Replace control unit

The engine is running erratically:

  • a) water entering the fuel tank - Drain sediment from the fuel tank
  • b) contact failure in the connections of the KMSUD harness - Eliminate contact leaks
  • c) air leakage into the intake manifold, bypassing the mass air flow sensor - Check connections, eliminate leaks
  • d) malfunction of the KMSUD wiring harness - Eliminate the malfunction
  • e) poor contact in the ground circuit connections - Eliminate the fault
  • Interruptions or failure of one of the engine cylinders:
  • a) violation or contamination of contacts in the ignition system - Eliminate contamination or leaks of contacts
  • b) carbon deposits on the heat cone of the spark plug - Replace the spark plug
  • c) the spark plug does not work - Replace the faulty spark plug
  • d) ignition coil malfunction - Replace the faulty coil
  • e) lack of contact in the injector connector or faulty injector - Check the connector on the injector or replace the injector

Increased crankshaft speed in idling mode on a warm engine:

  • a) air leakage into the intake system, bypassing the mass air flow sensor - Check connections, eliminate leaks
  • b) contact failure or failure of the electronic throttle - Check the connector, replace the electronic throttle
  • c) malfunction of the gas pedal position sensor or sensor circuit - Replace the sensor
  • d) increased gap between the phase sensor and the marker - Tighten the sensor mount
  • e) poor contact or faulty sensors - Check the connector, replace the faulty sensor
  • f) other malfunctions of the KMSUD - Eliminate the malfunction
  • g) the injectors are leaking or their nozzles are dirty - Replace the faulty injectors

Increased toxicity of exhaust gases:

  • a) increased resistance to air flow in the intake tract - Clean the intake tract or replace the air filter
  • b) increased gap between the electrodes of the spark plugs - Adjust the gap or replace the spark plugs
  • c) leakage of valves - Grind valves
  • d) malfunction of injectors (for clogging, leakage, poor spray) - Replace faulty injectors
  • e) violation of the timing phases - Correct the setting of the timing phases
  • e) increased oil waste - See “Increased oil waste”
  • g) KMSUD malfunction - Eliminate the malfunction
  • h) converter malfunction - Replace the converter

Engine does not develop full power:

  • a) increased resistance to air flow in the intake tract - Clean the intake tract or replace the air filter
  • b) increased coating of intake valves with carbon deposits - Clean the valves from carbon deposits
  • d) increased resistance in the exhaust tract - Clean the exhaust tract or replace parts of the exhaust system
  • e) timing violation - Carry out phase adjustment
  • e) wear on the camshaft cams - Replace the camshafts
  • g) excessive carbon formation in the combustion chambers - Clean the chambers from carbon deposits or replace the fuel and burn off the carbon deposits by driving at maximum power
  • h) the gap between the spark plug electrodes does not correspond to the norm - Check the gap with a round feeler gauge and adjust if necessary
  • i) reduced engine compression - Grind in the valves or repair the CPG
  • k) insufficient spark power - Replace the ignition coil or eliminate the malfunction
  • k) KMSUD malfunction - Eliminate the malfunction
  • Insufficient fuel supply:
  • a) low fuel pressure - Replace the pressure regulator, fuel pump, fine fuel filter or clean the fuel supply line, fuel receiver
  • b) clogged injectors - Replace faulty injectors
  • c) faulty injector windings - Replace faulty injectors

Engine overheats:

  • a) insufficient amount of coolant in the system - Add coolant. Check the system for tightness
  • b) the thermostat is faulty - Replace the thermostat
  • c) burnout of the cylinder head gasket - Replace the gasket, check the non-flatness of the mating plane of the cylinder head
  • d) slipping of the accessory drive belt - Replace the tensioner
  • e) violation of coolant circulation - Flush the cooling system
  • f) malfunction of the water pump - rotation of the hub or impeller, wear of the impeller - Replace the water pump
  • g) contamination of the outer or inner surface of the radiator - Clean the radiator
  • h) insufficient rotation of the electromagnetic fan clutch due to belt slippage - Eliminate the fan malfunction or malfunction

Low oil pressure or lack of pressure in the lubrication system:

  • a) jamming of the oil pump pressure reducing valve in the open position, breakage or weakening of the plunger spring - Eliminate the cause of the valve jamming or replace the plunger spring
  • b) oil filter clogged - Replace filter
  • c) clogged oil receiver screen of the oil pump - Clean the screen
  • d) sticking of the oil filter anti-drainage valve after the car has been parked for a long time - Replace the filter
  • e) breakage or weakening of the thermal valve safety valve spring - Replace the spring
  • e) engine overheating - Eliminate the cause of overheating
  • g) increased clearances in the oil pump, wear of pump gears - Replace the oil pump
  • h) increased clearances in the crank and gas distribution mechanisms in those units where oil is supplied under pressure - Repair the engine
  • i) low level in the oil sump - add oil to the recommended level according to the indicator
  • k) constant opening of the oil filter bypass valve - Replace the oil filter
  • l) the oil pump drive is faulty - Replace the defective drive parts
  • m) low-quality engine oil or one that does not correspond to the season of operation is filled in - Replace the engine oil. Flush the lubrication system
  • n) malfunction of the sensor or short circuit of the wire from the sensor to the signaling device to ground - Replace the sensor or eliminate the short circuit of the signaling device

Increased oil consumption:

  • - Oil leakage through oil seals and gaskets
  • a) destruction of the oil seals and wear of the crankshaft area under the working edge of the oil seal - Replace the oil seal. When the crankshaft is worn, use a spacer ring to install the oil seal
  • b) defect of sealing gaskets, warping of the adjacent plane of the part
  • c) clogging of the crankcase ventilation system;
  • d) sticking of the vacuum valve.

Increased oil waste:

  • a) high oil level in the oil sump - Drain excess oil
  • b) wear, coking of piston rings - Repair the engine
  • c) rupture of the vacuum valve diaphragm - Replace the diaphragm
  • d) destruction of oil seals - Replace the caps
  • e) the presence of cavities or non-cylindrical holes for the valve sleeve in the cylinder head. Increased gap in the valve sleeve-valve stem interface - Repair the engine
  • e) wear of CPG parts, cylinder scuffing - Repair the engine

Oil loss into the engine cooling system:

Cylinder head gasket leak - Replace cylinder head gasket.

Check the mating surface of the cylinder head for non-flatness

Knocks in the engine:

  • a) wear of the crankshaft liners - Repair the engine
  • b) wear of the connecting rod and piston group - Repair the engine
  • c) wear of the CPG - Repair the engine
  • d) the valve hydraulic pusher is faulty - Replace the hydraulic pusher
  • e) the hydraulic chain tensioner is faulty - Replace the hydraulic tensioner
  • e) increased chain elongation - uniform noise in the front part of the engine, increasing at medium speeds and variable loads - Check the increase in chain length, if necessary, replace the chains with sprockets as a set
  • g) scoring of the valve stem in the guide sleeve - Repair the cylinder head
  • h) settlement under load of the valve spring - Replace the spring
  • i) breakage of the spring of the automatic tensioner - Replace the tensioner
  • j) the crankshaft damper pulley is loose - Tighten the bolt
  • l) the generator bearing is faulty - Replace the bearing
  • m) water pump bearing knocking - Replace the pump
  • n) knocking of the bearing of the guide roller of the accessory drive belt - Replace the guide roller