High frequency whistling noise from the engine compartment

  • Hello all,

    Maybe someone has an idea - or has had the problem before.

    I have a high frequency whistling noise from the engine compartment in my 997.2 4s since the latest. It only occurs when the oil is at least 90deg. I first thought it was an airflow noise, but the pitch is too high and too fine for that. The noise is not dependent on the RPM or speed, is also well audible at a standstill at the traffic lights - is already quite loud ...

    I would argue with not knowing that it could be coil noise. Am at a loss as to where to look though. The engine compartment is nicely covered up, after all.

    Has anyone had anything like this before? Or would have any ideas?

    Greetings

    Al

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  • Hi,

    check the idler pulleys of the poly belt?

    Greetings Dirk

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    Wer fliegen will, muss nicht nur Flügel haben, sondern muss sie auch gebrauchen.

  • Hi Dirk,

    Rollers have been changed recently.

    But the noise is very digital. It starts "abruptly" at a certain time and remains absolutely constant in frequency and volume( no dependency on engine load or speed).

    Greetings

    Al

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  • Al,

    I don't know if this has something to do with your phenomenon:

    Check the system for aeration of the activated carbon filter in the tank. The electromagnetic valve is located to the left of the throttle valve (see picture, may look different depending on the vehicle model)).

    I think this is because the part is not always active (in my car only when the engine is warm) and when I hear noises from the thing (is more like a knock), these are engine speed independent.

    Greetings

    SJ

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  • Hello Al,

    do you have a new radio? Is the noise coming from the speakers? There was a case here recently.

    Greetings

    tkm

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  • Hello Al,

    do you have a new radio? Is the noise coming from the speakers? There was a case here recently.

    Greetings

    tkm

    Hi, no, not a new radio. The noise is definitely coming from outside. You can also hear the reflection (comes from below) if you stand somewhere next to a wall.

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  • Servus,

    My tip is the water pump - was similar with me. What do you have Km on the clock?

    VG

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  • Servus,

    My tip is the water pump - was similar with me. What do you have Km on the clock?

    VG

    The engine has 70tkm, the pump about 5tkm.

    I would say for pump the noise is too high frequency - and as I said, no dependence on the engine speed.


    Greetings

    Al

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