Whining noise on idle goes away when you throttle...

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Eegz39
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Whining noise on idle goes away when you throttle...

Post by Eegz39 »

Doesn't appear to affect anything but very annoying especially with the bar out. :)

Sounds like a belt or air-related. I've changed out the idle control valve sensor as covering over that seemed to quieten it but still no dice.

Mines a tenth-anniversary edition. Any ideas to get the MR back to full glory!

Thanks, John


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TonyleFrog
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Re: Whining noise on idle goes away when you throttle...

Post by TonyleFrog »

Is it a whine or more of a high pitched shriek?
The latter is a sure-fire sign of a slipping alternator belt.
It either needs tightening or replacing due to wear.

If you can record a video on your phone that might be helpful.
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Re: Whining noise on idle goes away when you throttle...

Post by jimi »

What number is your Anni ? Is it on the register ? https://www.mr2oc.co.uk/forum/198/161904.html
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Re: Whining noise on idle goes away when you throttle...

Post by MR2DI4 »

The alternator is probably stuffed.

If the battery is good and the belt is good then its the alternator.

The whine is really noticeable at idle. A diode or two has gone in the alternator and the three windings are no longer balanced. Harmonics occur and thats the whine you can hear.

Check the charge Voltage with a multimeter on idle, you probably no longer have 14.6 to 14.8V

The alternator should still be putting out 14.6V even at 750-850rpm, if its not the alternator is stuffed.

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Re: Whining noise on idle goes away when you throttle...

Post by nick »

Sorry but I can't resist it...................are you sure it is not coming from the passenger seat?

Seriously, alternator and belt a good start
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