Hi,
I was wondering if I could pick collective brains. As part of the rolling restoration on my Coupe I'm having a bit of trouble working out what is causing a noise when the engine is idling.
When started it makes a rhythmic sort of 'chirp' (not squeal) that goes away when the revs I raised. You don't notice it when driving, just idling. Even my daughter asked what the noise was! (Makes no difference if ac is on or off)
It sound like ancillary belt or something in that area so I removed the belt and ran it again - no noise.
I checked the alternator and that was quiet, I checked the ac pulley and that seemed quiet so I've changed the tensioner and fitted a new belt but the exact same noise is still present.
Using a mechanics stethoscope didn't seem to pin point it either. I'll try and get a recording.
Does anyone have any other ideas please?
Thanks,
Andy.
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Rythmic noise at idle - Absent with belt removed - Fixed!
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Rythmic noise at idle - Absent with belt removed - Fixed!
Last edited by Zummerset on Sat May 11, 2024 2:19 pm, edited 2 times in total.
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Rythmic noise at idle - Absent with belt removed
Water pump?
All good things come to those who wait. I'm really impatient which explains a lot.
F31 320i. Good car.
E89 20i Now fully dried
Z3 'free litre'. Project and a half. Complicated!
Mazda3 sold
Tatty old R56 Mini Cooper. Money pit!
F31 320i. Good car.
E89 20i Now fully dried
Z3 'free litre'. Project and a half. Complicated!
Mazda3 sold
Tatty old R56 Mini Cooper. Money pit!
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Rythmic noise at idle - Absent with belt removed
Good shout, but it has an electric pump as it's a Coupe.
Thanks though.
Thanks though.
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Rythmic noise at idle - Absent with belt removed
It’s got to be something the belt goes round.
Have you checked the crank pulley
Have you checked the crank pulley
2009 09 Carbon Black Cinnamon E86
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Rythmic noise at idle - Absent with belt removed
I did glance at the crank pulley, nothing looked odd. I think it is a harmonic type pulley but there didn't seem to be any play.
As you say it's got to be something the belt goes round as the noise is absent with it removed. Should be obvious....
As you say it's got to be something the belt goes round as the noise is absent with it removed. Should be obvious....
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Rythmic noise at idle - Absent with belt removed
Yes it’s a harmonic balancer pulley.
No splits in the rubber?
No splits in the rubber?
2009 09 Carbon Black Cinnamon E86
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Rythmic noise at idle - Absent with belt removed
Managed to capture some sound clips today.
1st clip is running with the belt, 2nd without.
In both clips there is a half second horrible noise on start-up which I also don't know what it is. Obviously not belt related as it does it on both.
On first clip the rhythmic noise is most obvious around 1m 30 and beyond.
Bit stumped what either noise is??
https://youtu.be/3KKOwDoP7U0?si=HcpfJQs2aDEa-NS8
https://youtube.com/shorts/IUTJyIqLstI? ... 8AFnxmd4tm
1st clip is running with the belt, 2nd without.
In both clips there is a half second horrible noise on start-up which I also don't know what it is. Obviously not belt related as it does it on both.
On first clip the rhythmic noise is most obvious around 1m 30 and beyond.
Bit stumped what either noise is??
https://youtu.be/3KKOwDoP7U0?si=HcpfJQs2aDEa-NS8
https://youtube.com/shorts/IUTJyIqLstI? ... 8AFnxmd4tm
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Rythmic noise at idle - Absent with belt removed - Fixed!
Just to follow up on this. It turned out the alternator pulley was faulty. I didn't realise the pulley has a one way clutch mechanism. Mine was seized so didn't slip in one direction.
I tried to replace just the pulley but it didn't come off, even using the correct tools, so bought a new alternator.
On to the next thing....
I tried to replace just the pulley but it didn't come off, even using the correct tools, so bought a new alternator.
On to the next thing....