Possible malfunctions - Diagnostics - Remedy
The electric fan of the engine cooling system is constantly running (even on a cold engine)
Open circuit in the coolant temperature sensor or its circuit - The sensor indicator is on and the circuits are checked with an ohmmeter - Replace the faulty sensor
The contacts of the relay for turning on the electric fan do not open - Check with a tester - Replace the faulty relay
Faulty controller or circuitry - Test controller or substitute with known good - Replace faulty controller
The engine takes a long time to warm up to operating temperature
Thermostat is faulty - Check the thermostat is working - Replace the faulty thermostat
Low air temperature (below -15 ° C) - Insulate the engine: install shields in front of the radiator, but do not block more than half of its area
Coolant level drop in expansion tank
Damage to the radiator, expansion tank, hoses, weakening of their fit on the nozzles - Inspection. The tightness of radiators (engine and heater) is checked in a bath of water with compressed air at a pressure of 1 bar - Replace damaged parts
Fluid leaking through coolant pump seal - Inspection - Replace pump
Cylinder head gasket damaged, block or cylinder head defective - Whitish emulsion on the oil level indicator.
There may be a lot of white smoke from the muffler and oil stains on the surface of the coolant (in the expansion tank).
Coolant leaks on the outer surface of the engine - Replace damaged parts. Do not use water in the cooling system, fill in coolant suitable for climatic conditions
Extraneous noises and knocks in the engine
Valve drive clearances not adjusted - Check clearances - Adjust clearances
Settlement or broken valve springs - Engine disassembly inspection - Repair engine
The timing belt is worn out. Faulty drive idler - Inspection - Replace belt. Replace the faulty timing chain tensioner
Knocking crankshafts and camshafts, connecting rod and main bearings, pistons, piston pins, play or seizure in the bearings of the generator, coolant pump - Check - Repair or replace parts
One or more power unit bearings have lost elasticity or collapsed - Inspection - Replace the bearing
Low pressure in the oil line at minimum idle speed, the pressure in the lubrication system of a warm engine must be at least 2.0 bar - Check the pressure in the lubrication system. You can measure the pressure by connecting a pressure gauge to the oil line by unscrewing the oil pressure sensor - Troubleshoot the lubrication system
Strong engine vibration
Uneven compression across the cylinders is more than 2 bar: gaps in the valve drive are not adjusted, wear or damage to valves, seats; wear, occurrence or breakage of piston rings - Check the compression. Compression must be at least 11 bar - Adjust valve clearances. Replace defective parts
Insulation damage of high-voltage devices and circuits - interruptions in sparking - Using an ohmmeter, check for an open or "breakdown" of the ignition coil windings and high-voltage wires - Replace the faulty ignition coil, damaged high-voltage wires.
Under severe operating conditions (salt on the roads, frost alternating with thaws), it is advisable to replace the wires every 3-5 years
The high voltage wires are connected to the ignition coil in the wrong order; one or more wires are disconnected – Inspection - Connect the wires according to the markings on the ignition coil
Defective spark plugs - Check spark plugs - Replace defective spark plugs
The gap between the electrodes of the spark plugs is not correct - The gap is 1.0-1.1 mm is checked with a round probe - By bending the side electrode, set the desired gap or replace the spark plugs
Strong deposits on the electrodes of the spark plugs; soot particles getting into the gap between the electrodes - Inspection.
According to soot, you can usually determine the performance of the spark plug and the condition of the engine - Clean the spark plugs with compressed air or mechanically. (Do not damage the insulator!). Identify and eliminate the cause of increased carbon formation in the combustion chamber, if necessary, replace the candles
Open or short circuit in the windings of the injectors or their circuits - Check the windings of the injectors and their circuits with an ohmmeter - Replace faulty injectors, ensure contact in the electrical circuits
Nozzles are leaking (overflow) or their atomizers are dirty - Check the tightness and shape of the nozzle spray jet - Dirty nozzles can be washed at a special Negerm stand Replace clean and heavily soiled nozzles
The idle speed regulator or its electrical circuit is faulty - The indicator may light - Replace the regulator with a known good one - Replace the faulty regulator
The supports of the power unit have lost their elasticity or collapsed, their fastening has weakened - Inspection - Replace the supports, tighten the fasteners
Increased content of harmful substances in exhaust gases
Nozzles are leaking (overflow) or their nozzles are dirty - Check the tightness and shape of the nozzle spray jet - Dirty nozzles can be washed on a special stand. Replace leaky and heavily soiled nozzles
Insulation damage on high voltage appliances and circuits - interruptions in sparking - to check high voltage wires and ignition coils, replace them with known good ones - Replace a faulty ignition coil, damaged high voltage wires. Under severe operating conditions (salt on the roads, frost alternating with thaws), it is advisable to replace the wires every 3-5 years
Defective spark plugs: current leakage through cracks in the insulator or carbon deposits on the thermal cone, poor contact of the central electrode - Check the spark plugs - Replace defective plugs
The phase sensor or its circuits are faulty - The signaling device is on - Check the serviceability of the phase sensor with a tester - Restore contact in the electrical circuits, replace the faulty sensor
Faulty coolant temperature sensor - Check the resistance of the sensor with an ohmmeter at different temperatures - Replace the defective sensor
Faulty throttle position sensor or its circuits - Warning light is on. Check the serviceability of the throttle position sensor - Repair the contact in the electrical circuits, replace the faulty sensor
One or both oxygen concentration sensors are faulty - the warning light is on.
You can evaluate the performance of oxygen concentration sensors and the reliability of their electrical circuit connections using diagnostic equipment - Repair damaged electrical circuits. Replace defective sensor(s)
Mass air flow sensor and its circuits are faulty - Warning light is on. Check the health of the mass sensor
Air flow rate can be used with diagnostic equipment - Repair the contacts in the electrical circuits. Replace the defective mass air flow sensor
The controller or its circuits are faulty - to check, replace the controller with a known good one - Restore the contacts in the electrical circuits. Replace defective controller
Leakage of the exhaust gas system in the area between the collector and the pipe of the additional muffler - Inspection at medium crankshaft speed - Replace the defective gasket, tighten the threaded connections
Faulty catalytic converter - Warning light is on - You can check the serviceability of the catalytic converter using diagnostic equipment - Replace the catalytic converter
Increased pressure in the fuel lines due to a malfunction of the pressure regulator - Inspection, checking the pressure in the fuel system with a manometer (no more than 4.0 bar) at idle - Replace the faulty regulator
The engine control system warning light comes on when the engine is running
The controller, sensors, injectors or their circuits are faulty. The fault may be temporary, in which case the warning lamp may turn off by itself without any intervention - See the previous troubleshooting sections. Full diagnostics of the control system is carried out using specialized equipment - If most of the sensors (except for the crankshaft position sensor) fail, you can drive to the place of repair on your own - Replace the faulty controller, sensors, injectors, wires
Separate sensors, injectors were disconnected (possibly for testing), after which the ignition was turned on (the engine was started). At the same time, the corresponding fault code is recorded in the computer's memory, which is not erased even after the electrical connections are restored - Remove the negative wire terminal from the battery terminal for at least 10 seconds. In this case, all fault codes are erased from the controller's memory