Method for detecting combustion defects occurring in at least one cylinder of an internal combustion engine during at least one combustion cycle, the method operating by analysing the values of a representative quantity of the gas torque deduced from the rotation of the crankshaft, the analysis of the said values being carried out on the basis of filtered values of the gas torque when a stabilized operation of the engine is established, characterized in that: a. For a four-cylinder engine, the analysis of the gas torque values comprises the analysis of the following three gas torque differences, a combustion defect being detected if at least one of these differences exceeds a threshold value: - a first difference equal, for a given top dead centre, to the difference between the filtered gas torque value two top dead centres before the given top dead centre and the filtered gas torque value at the given top dead centre, - a second difference equal, for a given top dead centre, to the difference between 1) the sum of the filtered gas torque value and of the filtered gas torque value two top dead centres before the given top dead centre, and 2) the sum of the filtered gas torque value one top dead centre before the given top dead centre and of the filtered gas torque value three top dead centres before the given top dead centre, - a third difference equal, for a given top dead centre, to the difference between the last filtered gas torque value before a detected combustion defect and the non-filtered gas torque value, and b. For a three-cylinder engine, the analysis of the gas torque values comprises the analysis of the following two gas torque differences, a combustion defect being detected if at least one of these differences exceeds a threshold value: - a first difference equal, for a given top dead centre, to the difference between the filtered gas torque value one top dead centre before the given top dead centre and the filtered gas torque value at the given top dead centre, - a second difference equal, for a given top dead centre, to the difference between the last filtered gas torque value before a detected combustion defect and the non-filtered gas torque value at the given top dead centre. a. For a four-cylinder engine, the analysis of the gas torque values comprises the analysis of the following three gas torque differences, a combustion defect being detected if at least one of these differences exceeds a threshold value: - a first difference equal, for a given top dead centre, to the difference between the filtered gas torque value two top dead centres before the given top dead centre and the filtered gas torque value at the given top dead centre, - a second difference equal, for a given top dead centre, to the difference between 1) the sum of the filtered gas torque value and of the filtered gas torque value two top dead centres before the given top dead centre, and 2) the sum of the filtered gas torque value one top dead centre before the given top dead centre and of the filtered gas torque value three top dead centres before the given top dead centre, - a third difference equal, for a given top dead centre, to the difference between the last filtered gas torque value before a detected combustion defect and the non-filtered gas torque value, and - a first difference equal, for a given top dead centre, to the difference between the filtered gas torque value two top dead centres before the given top dead centre and the filtered gas torque value at the given top dead centre, - a second difference equal, for a given top dead centre, to the difference between 1) the sum of the filtered gas torque value and of the filtered gas torque value two top dead centres before the given top dead centre, and 2) the sum of the filtered gas torque value one top dead centre before the given top dead centre and of the filtered gas torque value three top dead centres before the given top dead centre, - a third difference equal, for a given top dead centre, to the difference between the last filtered gas torque value before a detected combustion defect and the non-filtered gas torque value, and b. For a three-cylinder engine, the analysis of the gas torque values comprises the analysis of the following two gas torque differences, a combustion defect being detected if at least one of these differences exceeds a threshold value: - a first difference equal, for a given top dead centre, to the difference between the filtered gas torque value one top dead centre before the given top dead centre and the filtered gas torque value at the given top dead centre, - a second difference equal, for a given top dead centre, to the difference between the last filtered gas torque value before a detected combustion defect and the non-filtered gas torque value at the given top dead centre. - a first difference equal, for a given top dead centre, to the difference between the filtered gas torque value one top dead centre before the given top dead centre and the filtered gas torque value at the given top dead centre, - a second difference equal, for a given top dead centre, to the difference between the last filtered gas torque value before a detected combustion defect and the non-filtered gas torque value at the given top dead centre.