3022721 - S10 ENGINE WHILSTLING / SERVICES BELT NOISY'

A high frequency noise is heard from the engine, whose intensity varies with the number of revs
Results of the tests
0PRELIMINARY CHECKSAll OKProblems metOperation
Check the condition of the auxiliary drive belt and check that the tension is correct.See if the whistling stays constant as more electrical loads are conneced. Continue to Step 1Belt worn.Replace the belt Op.   1092G10 
Tension incorrectAdjust belt tension
The whistling noise increases.Continue to Step 1
1CHECKING ALTERNATORAll OKProblems metOperation

Check that the alternator is working properly, in particular

  • voltage regulator
  • the connections between the alternator and the battery
Continue to Step 2Defective voltage regulatorReplace the alternator Op.   5530A10 
Connections not correctRestore connections
2CHECKING AUXILIARY DRIVE BELTAll OKProblems metOperation
Check whether the whistling disappears when the belt is disconnected.
Do not let the engine run for long with the belt disconnected
Continue to Step 3The whistling disappears:Continue to Step 3
The whistling remains constantContinue to Step 4
3CHECKING AIR CONDITIONER COMPRESSORAll OKProblems metOperation
Check the air conditioner air conditioner compressor is working properly.Continue to Step 4Air conditioning compressor faultyRepair or replace the compressor Op.   5040A20 
4CHECKING BELT TENSIONAll OKProblems metOperation
Check the condition of the belt tensioner bearingsContinue to Step 5Fixed belt tensioner faultReplace the fixed belt tensioner Op.   1092G20 
Mobile belt tensioner faultReplace the mobile belt tensioner Op.   1092G14 
5CHECK ON CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentFault persistsSearch for the fault starting from another symptom'