Sorry if this issue has been mentioned before, haven't been on here for a while.

My car (petrol) has driven 65,000kms and recently noticed this whirring/whining noise coming from the rear. The sound increases are you accelerate. Could it be the differential? Is it still safe to drive?

If, on a clear road, you swerve the car from side to side, alternately placing load on each wheel bearing and the noise changes, it's normally a bearing. If not, it could be the diff. Past: FL2 TD4 HSE Auto
Evoque SD4 Dynamic Lux Auto
Present: Audi A3 S Line.

most likely the rear diff as it is a very common issue unfortunately.

Which model year is your car ?

the noise is constant even when swerving left right. Local mechanic guessing it's diff. If so how much would it be to repair and is it safe to drive? Mine is 2007 model, purchased in 2009. So I'm wondering if it's worth repairing or should I just sell it?

I have had the noise with (at different times) diff, xfer box, wheel bearing and noisy rear tyres and they all sounded the same to me. 3 x FL1 2 manual + 1 auto
5 x FL2 4 manual + 1 auto
Now Discovery Sport P250 MHEV SE

In the UK an indy will fit a refurbed diff for £700. Probably slightly cheaper if you buy a refurbed diff (£350-£450) and take it along to them as it will save them taking it to someone locally themselves.

Ref question about selling it on... seen this said a few times on here recently - never understand it. It's just a component gone wrong. Whether it's worth fixing depends on if you want to keep the car right now, we don't know where you are in your car lifecycle. If it's worth X and it costs Y to fix the diff, then you'll sell/trade the car for X-Y rather than X (assuming seller honesty and buyer due diligence). You won't be up or down either way. Personally I'd far rather keep a sorted car I knew than take a punt on another used vehicle.

Thanks for the responses, I might get some repair quotes and see. I am planning to upgrade to Disco 5 later this year. Very pricey though....

Huang if you are serious about parting with the car you have answered your own question  FL2 MY10 TD4 GS traded in at 2 years
FL2 MY13 TD4 GS Current

Hi Huang

It is most likely your rear diff pinion bearing that is failing, refer to Service Bulletin (LTB00342/2010)

https://www.lro.com/blog/advice/maintainin...-rear-diff

If you get your vehicle in for repair soon enough you Should only need to replace the bearings and upgrade your Haldex controller coupling to a generation 4. If your land rover dealer is worth their salt, they WILL know this fault. i have been quoted $2500 AUD in Perth for this repair. This may be a fair amount of cash, but a lot less than a replacement rear diff (which won't actually rectify the issue unless you replace your Haldex coupling with a Gen 4)

Its far more likely to be unusual wear on your rear tyres, believe me iv'e seen this on so many AWD platforms and its logical to start there first rather than jumping to conclusions.
Especially if you've rotated tyres which is not really recommended on AWD, especially "blocky" or "AT" tyres.
Do a search regarding noise from tyres. MY15
Tyre Pressure Monitoring System (TPMS)
Surround Camera System
InControl Apps soon to be replaced with CarPlay (WIP)
Meridian Premium Surround Sound
Digital Audio Broadcast
Timed Climate
Cruise ECO Data
Follow Me Home Reverse
Extra Features Menu
Picture In Motion
4x4i screen (WIP)
Digital Broadcast TV
Meridian Rear Media with WIFI
Factory Powered Tailgate
Blind Spot Monitoring (BSM)
Reverse Cross Traffic Alert (RCTA)
Electrochromatic Wing Mirrors (WIP)

Might pay to do a quick test. fold the back seats up and find an empty carpark. Get a friend to sit in the boot with his ear to the floor. drive slowly around and it should give you a good idea where the noise is coming from.