Omega Owners Forum
Chat Area => General Car Chat => Topic started by: TheBoy on 21 June 2024, 17:50:58
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Separating out into a new thread.
Got an intermittent buzzing from somewhere in the back, I believe to be in area of rear headlining or rear window, sounds like an airy wasp stuck in a confined space, or a relay chattering at high frequency.
Remove sigma pod containing the GPS antenna and DAB Band-L receivers, as it appeared to be coming from that area, and putting pressure on PCB changed the tone or eliminated it.
After a test drive with it removed the noise is definitely still there.
I had it present for long enough to do further tests. The noise disappears if:
any window slightly open
and door open
sunroof tilted or open
climate turned off
pressure applied to OS top of rear window and/or that area of roof.
Can it be cabin pressure in the car?
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Also, when it's making the noise, turning the climate fan down to 1 seems to stop the noise, turning up to 3 or higher seems to bring it on. 2 seems a bit inconclusive.
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Sorry, I meant nearside top half of rear window.
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Sounds like the extractor vents may be blocked or shut causing pressure build up
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funny. mine is exactly the same. only noticeable with blower on high and all windows closed. rear vent flap not stuck. so definately not electrical ( mine is more of a whistle ?)
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Sounds like the extractor vents may be blocked or shut causing pressure build up
That's now my thinking, just need to find where the exhaust vents are on an X351 XJ
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This is the noise, and how to get rid of it:
https://youtube.com/shorts/C7GYyt8ovZk
Views?
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And from the inside:
https://youtube.com/shorts/NzUeVWByNLg
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ah sorry. though we were talking omega !
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That has got to be airflow related surely, it’s so reminiscent of a dried out leaf stuck in a vent. What’s confusing is why it stops with pressure applied in certain places. :-\ I’ve had tinnitus for years but that would really get on my tit. :y
Hmm, I’m not so sure now. :-\ Time to find some access holes and pack some sponge around the rear roof to see what’s resonating. If I can help in any way just give us a shout. :y
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Jeez! I thought we were talking a very quiet humming noise, not a firkin great hornets nest type of noise :o
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Sounds like a window motor under stress, and applying pressure to the glass is like putting your finger in the way of the glass going up and it stops the motr lifing the glass.
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Does the rear screen leak?
Sounds like resonance of the rear screen possibly as a result of the bonding starting to fail.
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That would be infuriating....from an outsiders perspective that noise is funny is break.
Rather than a wasp or bee, sounds more like a lady bee pleasuring herself with something from lovehoney ;D ;D ;D
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That would be infuriating....from an outsiders perspective that noise is funny is break.
Rather than a wasp or bee, sounds more like a lady bee pleasuring herself with something from lovehoney ;D ;D ;D
And we all know how much bees love honey >:D
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Joking aside, the fact that pressing on the glass reduces it significantly, suggests that it's the glass making the noise.
As a temporary fix, a bead of silicone across the screen parallel to but away from the edge might dampen the vibration and therefore the noise.
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Joking aside, the fact that pressing on the glass reduces it significantly, suggests that it's the glass making the noise.
As a temporary fix, a bead of silicone across the screen parallel to but away from the edge might dampen the vibration and therefore the noise.
Pressing the roof also fixes it. I suspect, rather than vibration, its cabin pressure.
Think I've found the exhaust vents, so given them a blast with the airline, as it feels like this have a very fine mesh - having to go by touch, without removing the bumper (time is currently against me). Still can't find the openings in the boot though, doesn't appear to be in the wheel well, so might have to remove interior boot trim, but that again is a job for another day, probably not this side of it's 'bobs...
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They're generally outboard and down below bumper line. So definitely side panels out... On the Proper Car, it's literally one Torx screw for the net clip and four push pins. Aka a two minute job whilst waiting for the kettle.
On the Jaaag, you probably need to remove the doors and rear seats. >:D
It could also bee* the panel bond between the inner window aperture structure/roof cross member and the roof skin.
Does it buzz with the engine off? If not, then also consider the engine and gearbox mounts as it could be a contact transmission of vibration to the shell and, for the potential items I have suggested, may be exacerbated by a build quality/weakness at the back of the roof... The logic here being that the top of the glass is bonded to the roof skin and, in turn, the skin to the structure... A discrepancy in either bond will allow vibration/resonance. That noise is definitely a vibration or resonance rather than electrical, and whilst the cabin vents might be obstructed, that won't stop the movement that is allowing the vibration to occur. It may reduce the symptoms, but it won't cure the ailment.
Adding Dynamat or similar to the roof may also mitigate the sound.
*Terrible bee joke absolutely intended :P
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Its not too bad - boot floor out, rear boot scuff plate off, then a couple of clips per side....
...once you've emptied the boot of crap, and the side nets of crap ;D
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Vents allow air flow through, they appear to have rubber flaps in them that allow air out, and presumably stop air coming back in?
Difficult to get to due to looms - I think bumper will have to come off to inspect further, but an airline blows air through easy enough.
(https://theboy.omegaowners.com/jag_pics/odds/vent1.png)
(https://theboy.omegaowners.com/jag_pics/odds/vent2.png)
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let me rescale them, lol!
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In addition, how much shite is it possible to fit behind the trim panels in an XJ?
https://youtube.com/shorts/i91TH4gqlNA
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All well having the flaps there but is there gaps for the air to get to them?
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Also, when it's making the noise, turning the climate fan down to 1 seems to stop the noise, turning up to 3 or higher seems to bring it on. 2 seems a bit inconclusive.
The effects of climate change. ::)
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Also, when it's making the noise, turning the climate fan down to 1 seems to stop the noise, turning up to 3 or higher seems to bring it on. 2 seems a bit inconclusive.
The effects of climate change. ::)
That's actually cleverer than you thought it was ;D
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In addition, how much shite is it possible to fit behind the trim panels in an XJ?
https://youtube.com/shorts/i91TH4gqlNA
Do the rear seats fold?
The proper car has much of that gubbins across the back of the boot, battery included. That said, the right-hand quarter is pretty much filled with the hydraulics for the boot lid.
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Also, when it's making the noise, turning the climate fan down to 1 seems to stop the noise, turning up to 3 or higher seems to bring it on. 2 seems a bit inconclusive.
The effects of climate change. ::)
That's actually cleverer than you thought it was ;D
I'm actually cleverer than you think I am. :P