Hi all, on my seventh Full Fat RR but new to the site. Bought a 2013 L405 a few months ago. Question I can't find an answer to : if I accelerate from standstill, uphill, sounds like a pendulum weight moving back then forwards again. Sound seems to originate from under the front passenger seat. Any thoughts appreciated (no, I don't have a clock under the seat as afar as I'm aware !)

check for something in the passenger door pocket.  There is nothing that can't be fixed with a hammer😜😜
FFRR 4.4 SDV8 Autobiography Santorini Black.
KIA E-Niro 4+
2021 Discovery 5 D300 MHEV commercial

Only item in the door bin is the headphones in a fabric bag which would be more of a muffled noise if anything. The only way I can describe the noise is like a weight on the end of a vertical coil spring moving backwards under acceleration and then a bouncing noise when coming to rest. Odd I know! None the less I'll take the headphones out and see what happens

have a look under the car at the passenger seat location..

Check that the passenger side seat belt retractor is working correctly.
It is mounted in the bottom of the door pillar. G reg 2.5VM Vogue Portofino red 1991- 1999
V reg 2.5td P38 Rioja red 1999- 2006
53 reg td6 Vogue Oslo blue 2006- 2015
11 reg 4.4 TdV8 Vogue SE. Baltic blue 2015- date.
https://www.fullfatrr.com/forum/topic56162...tty+affair

Thanks for the tips. Had a look under the car and can't see anything loose or untoward. I'll check the seatbelt operation next.
A thought that crossed my mind today is the massage mechanism in or under the seat, but not having a mental picture of how it's put together I'm not sure. It makes no difference with a passenger on the seat, but I'll see what happens with the massage running. Either way it's not too much of an annoyance as it only occurs on fairly sharp acceleration uphill from a standstill. It's more a wooden or plastic type of noise, certainly not metallic. Something is moving backwards and then returning to its normal position with a kind of 'boing' sound, which is always exactly the same.

I have a 4.4 2017. I’m getting a whining noise on acceleration. Any ideas what that could be?

Thanks --
On my third Full Fat RR

After about two years I discovered the culprit in my case.....the air con filter housing box near the glove compartment has a curved hinged lid rather like a kitchen swing bin hence it was opening and closing on hard acceleration / deceleration. Very much doubt that's your problem though, more likely transmission noise of some sort if it's whining or air intake / turbo intake if it's whistling

Whining on acceleration, is probably drivetrain related, possibly transfer box or diffs. have the oils be changed on these? There is nothing that can't be fixed with a hammer😜😜
FFRR 4.4 SDV8 Autobiography Santorini Black.
KIA E-Niro 4+
2021 Discovery 5 D300 MHEV commercial

Whining noise under acceleration ? maybe her indoors has just seen the fuel bills
My Ex loved fast cars, but complained like hell if she had to pay for fuel, so I bought a Jensen. Her comments were along the extremely variety, once she found out about 8 or 9 to the gallon, she's long gone but I still have the car

On a serious note, have a look at any mounting brackets under the passenger side,any gearbox / driveshaft / transfer box / brackets or bushings ? Hope it's not serious.