Table 2.5. Search for causes of malfunction and methods of their elimination (Mitsubishi Matrix)

Possible causes of malfunction	Method of elimination
Low compression
Cylinder head gasket burnout	Replace the gasket
Worn or damaged piston rings	Replace the rings
Piston or cylinder wear	Repair or replace pistons/cylinder block
Worn or damaged valve seats	Repair or replace valves/valve seats
Low engine oil pressure
Low engine oil level in the pan	Check the oil level
Oil pressure switch sensor malfunction	Replace
The oil filter is clogged	Replace
Wear of gears or oil pump cover	Replace
Reduced viscosity (dilution or thinning) of engine oil	Change the oil and find the cause of the malfunction
The pressure reducing valve is stuck (in the open position)	Repair it
Increased bearing clearance	Replace
High engine oil pressure
The pressure reducing valve is stuck (in the closed position)	Repair it
Increased engine vibration
The front and rear engine mount brackets have become loose	Pull up
The gearbox support bracket has become loose	Pull up
The side engine mount bracket has become loose	Pull up
The central beam mount has become loose	Pull up
Gearbox support failure	Replace
Engine side mount failure	Replace
Front or rear engine mount failure	Replace
Noise from valves
Reduced viscosity (dilution or thinning) of engine oil (or low oil pressure)	Replace
Worn or damaged valve stem or valve guide	Replace
Incorrect operation of hydraulic compensators	Increase engine crankshaft speed to bleed hydraulic lifters or replace hydraulic lifters
Noise from connecting rod or main bearings of the crankshaft
Insufficient oil flow through bearings	Check the engine oil level
Reduced viscosity (dilution or thinning) of engine oil	Change the oil and find the cause of the malfunction
Increased bearing clearance	Replace
Timing Belt Noise
Incorrect belt tension	Adjust belt tension Low coolant level
Coolant leaks
Radiator or heater hoses	Repair or replace parts
Radiator cap malfunction	Install correctly or replace
Thermostat housing	Replace the gasket or housing
Radiator	Replace or repair
Coolant pump	Replace the parts
Clogged radiator
Foreign particles in coolant	Replace the coolant
Abnormally high coolant temperature
Thermostat malfunction Radiator cap malfunction	Replace parts Replace parts
The flow of coolant in the cooling system is obstructed	Clean the cooling system or replace parts
Loose or broken alternator drive belt	Adjust tension or replace
Coolant pump malfunction	Replace
Radiator electric fan malfunction	Repair or replace
Low coolant level	Top up the coolant
Abnormally low coolant temperature
Thermostat malfunction	Replace
Coolant temperature sensor or its wiring is faulty	Repair or replace
The radiator electric fan does not turn on
Faulty: Coolant Temperature Sensor, Radiator Fan Motor, Radiator Fan Motor Relay, Wiring or Fuse	Repair or replace
Leakage in the exhaust system
Loosening of fastenings at joints	Pull up
Defective exhaust pipes or muffler	Replace or repair
Extraneous noise from the exhaust system
Burnout of partitions in the muffler	Replace
Defect of rubber-metal suspension bracket	Replace
The exhaust pipe or muffler is in contact with the body	Correct it
Defective exhaust pipes or muffler	Repair or replace