Clogged oil filter
Clogged fuel filter
Correct injection timing
More supply of fuel
More supply of air
Incomplete combustion of fuel
Defective oil filter
High air draft
High circulation of water
Radiator core blocked
High water level in radiator
High water level
High oil level
Faulty water pump
Faulty injector
High fuel in tank
Low fuel in tank
High compression
Weak compression