Hi guys,

I have a whistling noise when the car (C2 MY99) is hot. The noise is engine speed dependent. It is penetrating in the interior when it is audible.
It has no false air holes and is fogged.
So far, I have only noticed it when I parked the car hot and drove on afterwards.

When stationary the noise also occurs, I can really hear it at the back of the engine though as the 6 cylinders are bubbling away comfortably.
I could be imagining that it's coming from the right side (bank 2) and maybe also in the servo pump area.

Pentosin was way too much in there.
Please listen in and let me know what you think.

It's not easy to record, and hard to hear depending on your terminal, but here's the youtube video for it....

 

Could be alternator whine. Did you just install an amp for the sound system...?

 

My 99 does this too. More pronounced when it’s hot outside and it seems to go away around 4K RPMs (but that could just be other sounds over powering it). I don’t think it’s anything to worry about.

 

Idler pulley on its way to failure? Seriously though, you need to get the RPMs up. I don't let mine doesn't go below 4,000 unless I am stopped!

 

finally a pragmatic solution

 

yes I have... but you can also hear it when I turn off the music.
It also sounds more technical, and I would expect to hear the noise even with the engine home open if it is the alternator,
What do you think is the reason that an amplifier could interfere with the alternator?

 

The amps ground wire is not big enough or has bad connections. Yes alternator whine will still happen when music is off.

To troubleshoot, disconnect all + power to the amp, see if alt whine subsides.

 

I can't believe it, but you are right.
It is the amp!
Thank you very much. Now I'am searching the reason or better the solution ;-)

 

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