During engine operation, some malfunctions may occur:
- - the engine does not start;
- - the engine is running unstable;
- - high or low crankshaft speed at idle;
- - increased toxicity of exhaust gases.
You can also look at the article - “Possible malfunctions of the ZMZ-40522, ZMZ-40524 engine.” There are detailed descriptions of faults and methods for correcting them.
Let's consider the causes and methods of correcting these defects and some others:
- Cause of malfunction
Elimination method
Engine does not start:
- Fuel supply is interrupted
Check the fuel pump fuse
- fuel pump does not work
Check the condition of the contacts in the connections of the pump, pump relay and start relay
- valve timing is disrupted
Restore phases at a service station
- fuel system pressure reducing valve has failed
Replace valve
- fuel filter is clogged
Replace filter
Ignition system is faulty:
- contact is broken in the circuits of the ignition coils and the control unit
Restore contact
- ignition coil failed
Replace the coil
The engine is running erratically:
- Water entering the fuel tank
Drain the sediment from the tank
- Air leaks through leaks in the intake system, crankcase ventilation or idle air control
Eliminate leaks in connections
Interruptions or failure of one of the cylinders:
- soot on the spark plug or spark plug failure
Clean off carbon deposits or replace spark plug
- injector contact is broken or the injector is out of order
Restore contact or replace injector
- spark plug tip is broken
Replace tip
- control unit is faulty
Replace block
Interruptions or failure of two cylinders:
- ignition coil is faulty
Replace the coil
- control unit is faulty
Replace block
High crankshaft speed in idle mode on a warm engine:
- Leaky connections between the hoses of the crankcase ventilation system and the idle air control
Eliminate leaks in connections
- The contact of the idle speed regulator is broken or the regulator is faulty
Restore contact or replace regulator
- The contact of the sensors of the engine control system is broken or the sensors fail
Restore contact or replace faulty sensors
Increased toxicity of exhaust gases:
- CO regulation is broken
Adjust the CO content with the adjusting screw on the mass air flow sensor
- Valve seal is broken
Lap the valves
- Oil seals are worn out
Replace caps
- The contact of the coolant temperature sensor is broken or the sensor is faulty
Restore contact or replace sensor
- CO regulation is broken
Adjust the CO content with the adjusting screw on the mass air flow sensor
- Valve seal is broken
Lap the valves
- Oil seals are worn out
Replace caps
- The contact of the coolant temperature sensor is broken or the sensor is faulty
Restore contact or replace sensor
- Wear of parts of the cylinder-piston group
Repair the engine
Engine does not develop full power:
- The air filter is dirty
Replace the filter element
- Fuel filter clogged
Replace filter
- Air throttle valve does not open fully
Adjust the damper drive
- Decrease in fuel pump performance
Replace the pump
Engine overheating:
- The tension in the drive belt of the water pump and generator has weakened
Adjust belt tension
- Thermostat is faulty
Replace the thermostat
- Insufficient amount of fluid in the engine cooling system
Add coolant
- Severe contamination of the radiator
Rinse the radiator with a stream of water
- Electric fan is faulty
Check the fan motor, sensor and relay. Replace faulty components
- Water pump is faulty
Replace the pump
Low oil pressure:
- Faulty or clogged oil pressure relief valve about the pump
Wash valve parts or replace faulty parts
- Engine overheating
Eliminate the cause of overheating
- Wear of oil pump parts
Replace the pump
- Wear of main bearing shells
Replace earbuds
Increased oil consumption:
- Piston rings are worn or coked
Repair engine
- The crankcase ventilation system is broken
Rinse system parts
- Oil seals are worn out
Replace caps
- Oil leakage through gaskets and seals
Fix leaks, replace gaskets and seals if necessary
Knock - in the engine:
- The hydraulic pusher is out of order
Replace the hydraulic pusher
- The hydraulic chain tensioner has failed
Replace the hydraulic tensioner
- The connecting rod and piston group is worn out
Repair engine
- The chain tensioner shoe is worn
Replace shoe