Guys,

This is a really difficult one, no-one I've taken it to seems to know what it can be, half the people can't even hear the noise!

At 1900-2300RPM under load I get a noise that almost makes your ears want to pop. It sounds like a reverberation noise or intake related noise, but you can't feel it through the car at all. At that RPM under no load I get no noise, after 2300RPM the noise goes away and is soon replaced by engine noise. Road speed is irrelevant. It is specifically RPM AND load related. It "feels/sounds" as if it's from the front of the car rather that underneath me or behind me, so think I'm right to rule out the gearbox for now?

I've replaced the exhaust from the cats onwards (not inc the cats).
Replaced the engine mounts.
Replaced the main gearbox mount.
Removed and refitted the whole intake assembly.

RPM & Load = Noise
RPM No Load = No Noise

The only difference between those who scenarios is throttle/air intake, am I right?

So that is still pointing to some sort of intake noise?

What can I try next? Could there be an issue with the Supercharger? I've not heard of this problem relating to a failing SC before.

Worth noting that the car is relatively high mileage at 170,000 miles.

Dan 

no noise from mine dan but on a2005 mine has only done 65000 not broke in yet

not sure what rpm the sc kicks in , so would it be idle up to 2300 rpm?..have you checked the sc oil level Dan.. ... - .- -.




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Think the s/c is engaged constantly as it is driven by the crank pulley - have you been through the intake all the way to make sure there is not a sensor disconnected thinking about it are there any faults registered

No faults registered last time I checked on the OBD. Wondering whether to send it to LR for a check on testbook to see if they can give it a full electronic workdown. Trouble is I don't rate many LR garages highly on anything over 3 years. 

Take the panel filter out and do your test again ...

My alternator was whining and that was making a noise that I thought was an intake noise/issue. Mine also made the noise at idle too. Mine had done 85k when the alternator went. The supercharger will work constantly.

You need someone with chassis ears to have s look and listen to it.

Can you post up a video of the noise?

Cheers Alex

2018 Skoda Kodiaq vRS
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2007 M5 Touring
2005 Range Rover Vogue SE Supercharged
2004 SL55 AMG

Ian - will try that...

Zarnd - oddly I can't ever record the noise. Imagine humming to yourself, it's always much louder to you than those around.. 

Did you do what I suggested previously and drive the RR with the pollen filter assembly removed ? This will give you more indication of the possible source of the noise. Stolen / Gone: 2006MY Supercharged LPG Autobiography - Zambezi Silver with Sand/Jet/Jet Oxford Leather.....

Only took 3 months for me to try this! I swear, since going self employed I have so little time my personal life moves at a glacial pace!

No difference with Engine cover and air filter housing removed. I can hear the SC much more and it sounds normal but this mystery noise is still the same volume/frequency etc.

Going to investigate prop joints/bearings next I think, any other suggestions? 

On my freelander diff bearing going, the drone noise appeared under load initially in 3Rd and 4th gears only, so it's possible to be drivetrain related. However it did get progressively worse to be noticeable through all shoes and gears over time.

What type of sound is it? Metallic? Low pitch, high pitch. Booming, etc etc. V8 or else ...

I recon it's a cat breaking up inside, they separate, sit funny and reverberate... my nearside one is doing it, sometimes the noise is awful, other times mine shuts up but every one will be different...

Give it a whack with a rubber mallet and see if they rattle at all.... Then tap them with a metal hammer, they should sound the same... any difference points to the problem....  Pete

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2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
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Fisha - Low pitched booming that seems impossible to record on my phone or dashcam. Almost feel it in ones chest rather than ears. Going to start throwing money at UJ's etc I think...

Haylands - good shout, although I have replaced the exhaust up to the cats, they aren't particularly easy to get to - but I think they should be investigated more thoroughly. 

Just an update...

Currently driving round with the engine covers off - the mechanics seem to think it's the Supercharger. At 175K it's easy to make assumptions.

It's going in next week for them to cut the SC belt and then see if the noise goes away - if it does, a new SC will be fitted at enormous expense... 

Dan, if it's the S/C it may just need new bearings, worth a strip and look see if it does turn out to be it... Did you play tunes on your cats..?? Have you tried removing the air filter and running it... you never know...  Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-