198001933 - S012 CYCLICAL ENGINE BUZZING

There is a loud and constant noise coming from the engine area that occurs at constant intervals.

		TEST RESULTS
1	AUXILIARY UNITS BELT CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check whether the noise disappears if the belt is disconnected	Move on to Step 2	1. The whistling noise stops2. The whistling noise remains constant	1. Continue as instructed in the    See table S010 ENGINE WHILSTLING / SERVICES BELT NOISY2. Move on to Step 2
2	ALTERNATOR CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the alternator and in particular- the condition of the bearing- the correct fastening of the pulley	Move on to Step 3	1. Alternator bearing damaged2. Incorrect pulley fastening	1. Replace the alternator    Op. 5530A10 ALTERNATOR - R+R 2. Restore correct pulley fastening    Op. 5530A30 ALTERNATOR PULLEY OR FAN - R+R WITH ALTERNATOR REMOVED
3	TIMING BELT TENSIONING CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check that the belt tensioning is not excessive	Move on to Step 4	Excessive belt tensioning	Restore the correct timing belt tensioning.
4	TIMING BELT TENSIONER CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the belt tensioners and in particular the condition of the corresponding bearings.	Move on to Step 5	1. Fixed belt tensioner bearing damaged2. Moving belt tensioner bearing damaged	1. Replace the fixed belt tensioner    Op. 1092G20 ENGINE COMPONENT SINGLE BELT FIXED TENSIONER - R + R 2. Replace the moving belt tensioner    Op. 1092G14 ENGINE COMPONENT SINGLE BELT MOVING TENSIONER - R + R
5	WATER PUMP CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the water pump and in particular the condition of the bearing	End of diagnosis	Water pump bearing damaged	Replace the water pump    Op. 1088C10 WATER PUMP - R + R     Op. 1088C14 WATER PUMP - R + R WITH TIMING BELT(S) REMOVED