16 · Diagnostics

S12 Cyclic engine droning

Fault diagnosisS12 Cyclic engine droning

There is a constant load noise coming from the area of the engine, which is repeated at regular intervals

Step	Test procedure	Result	Action
0	PRELIMINARY CHECKS Check the condition and tension of the auxiliary shaft drive belt	OK	Move onto step 1
0		Tension not correct	Replace the beltOp. 1092G10 End of diagnosis
1	AUXILIARY DRIVE BELT CHECK Check the belt tensioners and, in particular, the bearings	OK	Move onto step 2
1		Belt tensioner bearings damaged	Replace the belt tensioner (see Assembly 1092G) End of diagnosis
2	WATER PUMP CHECK Check the water pump and, in particular, the condition of the bearing	OK	Move onto step 3
2		Water pump bearing damaged	Replace the water pumpOp. 1088C12 End of diagnosis
2	WATER PUMP CHECK Check the water pump and, in particular, the condition of the battery, making sure it is correctly fixed	OK	Move onto step 3
2		Pulley damaged or fixing incorrect	Renew the correct fixing or replace the pulleyOp. 1088C24 End of diagnosis
3	ALTERNATOR CHECK Check the alternator and, in particular: the condition of the bearing the correct fixing of the pulley	OK	Move onto step 4
		Alternator bearing damaged	Replace the alternatorOp. 5530A14 End of diagnosis
		Pulley fixing incorrect	Restore the correct pulley fixingOp. 5530A30 0 End of diagnosis
4	CORRECT OPERATION CHECK Check that the fault is no longer present	OK	End of diagnosis
4		Fault persists	Incorrect selection of diagnostic procedure

Parts & tools for this job For 1997 Alfa Romeo 156

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