3308710 - S05 ENGINE HISSING

There is buzzing (low frequency noise) coming from the engine, whose intensity varies with the number of revs

		Results of the tests
1	CHECKING AIR CIRCUIT	All OK	Problems met	Operation
	Check the condition and seal of the air supply circuit	Continue to Step 2	Circuit component damaged	Replace component (See Assembly 1048A)
2	CHECKING ENGINE EXHAUST	All OK	Problems met	Operation
	Check the condition and the seal of the engine exhaust pipes	Continue to Step 3	Pipe, silencer or connector damaged	Replace the components (see Assembly 1076B)
3	VALVE LEAKAGE TEST	All OK	Problems met	Operation
	Check the condition and the seal of the timing valves	Continue to Step 4	Valves damaged	Replace the component (see ENGINE OVERHAUL, Subassembly 1016)
4	HECK ON CORRECT OPERATION	All OK	Problems met	Operation
	Check that the fault is no longer present	End of diagnosis	Fault persists	Search for the fault starting from another symptom'