Noise from driveline - speed/load insensitive

[SuperMono]

Last week I swapped back to road tyres from the muddies and noticed a new noise from what has otherwise been a very quiet 200K+ TDV6 'S'.

Looking for a few hints as so far I haven't been ably to clearly identify the cause.

It isn't very loud, my wife can't notice it and fitting the KM2s will mask it.
The noise is apparent from about 15kmh up but is not apparently sensitive to speed or load, no change in pitch, volume or presence.
It is not from the engine as it isn't present when stationary but is if you select neutral and kill the engine at low speed (rolling at 15-20kph).

I can best describe the noise as similar to:
1: wind noise on an old roof rack.
2: bearing loose in a housing (growl, growl)
3: turbulence or air in a fluid transfer pipe.

At first I did think it was wind related, but I'm not convinced.
I did fit one of the Green Oval radiator protection plates so might tape that over just to rule it out.

Otherwise I suspect something from the transfer case out to the wheels.
Next step is to remove all of the protection plates and have a good look and feel around all the bits that rotate.

Any clues out there :confused:

[ADMIRAL]

[QUOTE=SuperMono;1770271]Last week I swapped back to road tyres from the muddies and noticed a new noise from what has otherwise been a very quiet 200K+ TDV6 'S'.

Looking for a few hints as so far I haven't been ably to clearly identify the cause.

It isn't very loud, my wife can't notice it and fitting the KM2s will mask it.
The noise is apparent from about 15kmh up but is not apparently sensitive to speed or load, no change in pitch, volume or presence.
It is not from the engine as it isn't present when stationary but is if you select neutral and kill the engine at low speed (rolling at 15-20kph).

I can best describe the noise as similar to:
1: wind noise on an old roof rack.
2: bearing loose in a housing (growl, growl)
3: turbulence or air in a fluid transfer pipe.

At first I did think it was wind related, but I'm not convinced.
I did fit one of the Green Oval radiator protection plates so might tape that over just to rule it out.

Supermono, If the tyre change has initiated the noise, I would be looking at wheels and tyres first. Swap them around, or get hold of a std set that you know are not causing any issues. Likewise anything that has changed or has been changed should be eliminated first.

[SuperMono]

Not the tyres, makes the noise with the muddies on, just have to 'listen' for it as the increased tyre noise masks it out.

Still a mystery at the moment.

Edit: I have two sets of wheels, one set with KM2s, one set with standard road tyres. Any decent road use and the road set goes on, noise wasn't apparent about 1month ago when last on the 'quiet' tyres.

Something to note: The front bushes are shot and need to be replaced, but the noise doesn't seem to be influenced by bumps or steering/throtle inputs.

[Graeme]

The toe is likely to be out if bushes are shot, which could cause noise with any tyres.

[ADMIRAL]

A few queries which could help isolate your noise.

Does the noise change in pitch as speed increases ?
Does the noise pitch change if you vary the load, like swerving or going around a corner left or right?
Does the noise change or disappear under braking ? Likewise if you coast down a hill. ( throttle off )

[PeterOZ]

my 07 D3 148k has a smiliar noise, comes in though at about 40 kmh and quite notiable as you back off throttle. It is best describved as some sort of resonace, bit like a bearing but there is also a vibration that can be felt.

had it to LR numerous times and they could never find it and the couple of times I went for a drive with the tech the noise was not present, highly embarrassing.

Seems to be drivetrain related but as to what IO have no idea. Possibly a bearing in transfer case as one went when the car was quite new.

Goes to MR Redcliffe in Dec for first service with in Dec so will ask them to look into it.

Still under LR extended warranty so if a major repair would hope i'm covered.

[SuperMono]

The toe is likely to be out if bushes are shot, which could cause noise with any tyres.
Possible and bushes will be replaced next month regardless.


A few queries which could help isolate your noise.

Does the noise change in pitch as speed increases ?
Does the noise pitch change if you vary the load, like swerving or going around a corner left or right?
Does the noise change or disappear under braking ? Likewise if you coast down a hill. ( throttle off )
No
No
No


my 07 D3 148k has a smiliar noise, comes in though at about 40 kmh and quite notiable as you back off throttle.
......
Seems to be drivetrain related but as to what IO have no idea. Possibly a bearing in transfer case as one went when the car was quite new.

Thanks, transfer case bearing has been a nagging thought.

Yesterday I had a good dig around underneath and aside from some remaining mud (baked hard) lightly touching 1 rear inner CV could not spot anything obvious. I also had a close look at the wear patterns on all 4 tyres, nothing apparent.
Tomorrow I am going to shuffle them around a couple of times to check before the muddies go back on for Sunday.

I am a little suspect of the front diff for no reason other than I am lost for other ideas that convince me.
Car did its first 180,000+ km on the highway working lightly.

At least with the muddies on the noise will be 'missing' :)