2017 SDV8

Recently had my ARB D bushes and links changed, as I had a slightly annoying rattle over bumpers and the car seemed to rock when cars went past and I was stationary. This was a little over a month ago and has been knock free and much tighter to drive.

Had to do a lot of driving this week and in return journey a knock appeared (different to original knock) seemingly almost immediately got a lot worse. It is a near constant rattle/knock and I can feel it through the floor. It seems to be both sides, but more pronounced in the left.

Checked the links are still attached, look fine. Front arms didn’t look the best but not awful, had a quick inspection and confirmed by local mechanic that nothing seemed out. No time to get it booked in til week after next and I am puzzled. Performed the brake check to see if it makes it knock, it does not. Driving seems to set it off and the more uneven the road the worse it is. Weirdly it basically drives ok, doesn’t feel brand new or perfect but basically fine?

Anyone got any ideas what could rattle/knock all of a sudden? Usually this is a gradual process…

Undertray?
ARB Bushes?
Front knuckle top mount cracked?

No visible under tray hanging off and I inspected the knuckles which look ok (thankfully!)

Will obviously get it inspected, but I’m wondering after a search on here if it is valve block related or the bar itself

The block is on the passenger side, so it could be. Kev

2014 L405 RR Vogue SE 4.4 SDV8 in Corris Grey
2010 L320 RRS HSE 3.0 TDV6 in Stornoway Grey

It could also be one of the pipework support bobbins has come away from it's fixing, allowing one of the pipes to rattle on the subframe or body.

They look like this, they should have another threaded part on the bottom... They "look" OK and in one piece till you move them..!!

Click image to enlarge

They're the ones - changed three on mine...

Super useful stuff guys thank you. I noted a post about the pipe work rattling, will definitely look at this.

Haylands - where are these and what is the function? Also if have part numbers would be mucho useful. No worries if not

Drove to Ayelsbjry on back roads yesterday and the knocking/rattle was horrendous, worse than before. Trying to diagnose symptoms

Events occurred to produce rattling

- driving (lol)
- Low(er) speeds it seems more notable and the rattle part is loudest (under 45mph)
- Above 45mph rattle disappears, but knocking resumes over uneven road surface
- 60mph + it’s all but gone, unless mega crap road surface and again more knocking no rattle
- Uneven road surface triggers it
- Return journey was MUCH less noticeable today?? Weird.

Related/unrelated, the car sort of shimy’s across cars eyes at motorway speeds, it did this much worse before ARB links/d bushes changed. Still present though
- ride is noticeably harsh for a RR and crashy from rear on potholes

Here's the parts catalogue pictures, the insulators are at location 2C239 in both images

Thanks for that. I will definitely look at these.

Small update, on a return journey home the TPMS pinged, I checked the display and it seems the N/S was over inflated (40) and the ping was caused by a low warning on the O/S which was down to 30. So I checked and increased/decreased to correct pressures.

Drove the car and it has significantly reduced the rattle part of the sound, but the knocking is still present although it seems less intrusive and reduced somewhat, but definitely still present.

At motorway speeds it is all but eliminated, present still is a small shimmy when going over cats-eyes and this (for me) narrows it down

- Low speed symptoms
- exaggerated pressure differential made it worse
- All but gone at higher speeds

So I think it appears to me to be a control arm issue as that what seems most logical. Will have it inspected properly soon and get the necessary parts replaced.

Car just ticked over 64k, so assume this is in-line with general replacement mileage.

Will report back!

Update on this, I have been busy with things and not needed the car, so I have not organised any review or parts yet.

Drove it for first time in a week and the noise has completely gone

WTF! Not sure if the cooler weather has something to do with it, I will keep monitoring it but this now doesn't sound like control arms and maybe the ACE valve block,

I don't have a service record of the fluid or filter being changed, assume this is overdue! So might start there

Could be the upper ball joint which is bizarrely on the bottom of the hub. Have had to do the same passenger side twice on mine within about 5000 miles. Gives a dull knocking sound on uneven surface but really hard to find any movement in it while still on the car!

That’s useful info thank you. Seems to be the way with these, hard to find play when 2.5t is pushed down on them

Update on this. Odd one, hopefully useful to anyone chasing this,

Essentially the knocking came and went over the months/miles. Sometimes it would be really bad, other times silence, weird. But it always came back. Uneven surfaces tended to trigger it, but then you would hit a bump and it wouldn't rattle or knock. The sensation could be felt through the footwell and seemed to be mostly coming from the N/S.

I then developed a trademark suspension knocking noise consistent with the lower arms. The ride was also trash and quite wobbly up front. The knocking noise begun to get louder from the original horrible sound I have on/off very distinctive and not to be confused with the "typical" suspension rattle I was getting from the front arms.

I decided to get the arms replaced, ordered gen front and Delphi rear arms (front) from Maltings and got these fitted.

Drives great and thankfully it really improved the ride! The drive back home was bliss and it felt like the car was finally sorted.


But it wasn't!! 15 miles later and the knocking returned. This time, it was REALLY loud and seemed 10x worse than before. I then suffered a CV noise and the boot split throwing grease everywhere and needing a new drive shaft. Two mechanics advised this could be the cause of the knocking noise, so I was tentatively excited to get it back with the noise finally gone. Sadly the noise was still present It wasn't too bad, so I took on a 30mile trip and 1 mile from home the noise got much worse.

I took it on holiday and it continued to knock, but didn't seem so bad. Had considered selling at this point as was bored to tears with constant garage trips. About 15 miles from home the knocking returned again with vengeance and this time appeared to have "moved" to the O/S and I could feel the knocking under my feet.

Drove it to a garage and had a chat, we both suspected that the ARB bushes were to blame as the noise moved from side to side. Got these replaced today and the bushes were dead. 4000miles + 10 months give or take - don't fit Feb Bilstein ones!!!!

Happy to report the noise has finally gone and I can now enjoy the car again.