Recently I have noticed that whilst driving there is a very high pitched whining coming from the front of the car. On closer visual inspection with the engine running I opened the bonnet to try to locate where the noise was coming from. The sound seemed to be originating from around the alternator, near where the cam belt is. It has been getting louder recently and the car is due for a new cam belt in 3000 miles or so. The noise remains constant as I turn the wheels so presumably it isn't the power steering pump.

Can anyone clarify what is actually the problem or how to go about diagnosing it? I have had the EPC light come on on the dash board which I presume is due to one of the engine parts being faulty?

  • What does EPC stand for?
    – Zaid
    Jan 3, 2016 at 20:49
  • Electronic Power Control - I think that is a name specific to Volkswagen cars, I don't know what other manufacturers call it. Jan 3, 2016 at 20:52

2 Answers 2


Diagnosing noises when you're thousands of miles away isn't going to be easy, but here are a few tips to help you out:

  • remove the serpentine belt and run the engine

    If the noise stops, you know that the noise source is something that is running off the serpentine.

  • inspect the belt for loss of tension

    Loose belts are notorious for squealing

  • spin the pulleys by hand

    The pulleys should spin relatively easily without any binding. Binding would indicate that a bearing has gone bad and could cause noise

  • use a stethoscope

    I've never used a mechanic's stethoscope personally, but this is a good way to pinpoint the cause for the ruckus

  • So as far as I can tell there is no loss in tension of the belt - I am no expert but its does look quite warn on one side. I will try the other options at some point, I had never heard of a "mechanic's stethoscope" before but I might look in to it also if the others haven't found the source of the strange noise. Jan 3, 2016 at 22:10
  • 2
    @MaxGoodridge You can use a piece of rubber hose in lieu of the stethoscope. Or a solid wooden stick. Either will transfer the noise enough to be able to isolate it by just poking around.
    – race fever
    Jan 4, 2016 at 2:40

I took the car to the dealership for a full cam belt, belt tensioner, idler pulley and water pump replacement and the noise hasn't happened since!

I guess one of the parts that was changed during the maintenance must have been worn or damaged or the belt was rubbing on something that it should not have been.

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