CLONKING/KNOCKING when accelerating, or taking of
 

I am getting a clonking/knocking noise when accelerating, and selecting gear 1,3,4?

what could it be??

Mounts or bushes?

Mine does this too.(v70 d5)i've changed the lower control arm bushes and the top engine mount,yet i still have the noise.I wonder if it might be one of the lower engine mounts,or a gearbox mount? It's very frustrating as i can't pinpoint it.I think i'll have to get my brother to stick his head in while i drive round a bit.He'll like that, as he owes me one for sitting in his boot trying to find a clonking noise on his s40.(rear anti roll bar bushes)

piggy

Showned some one today and they go its the shock absorber, which i doubt.. so what could it be, my engine mount is slightly split,, would that be causing the problem..

If the top mount is split then this needs to be replaced as a process of elimination.

After fitting 18" Nebulas to my V70(was running 17" before), got the same noise you described. Aparently it has been kicking up stones onto the tray of the front struts. Stones cleared, noise gone.

Hi,

This has happened after i fiited nebulas too??

so how did you clear these stones? where were they stuck

On the front strut there is a tray/ support sort of thing on which the lowest coil of the spring sits on. Thats where my local inde told me he cleared it from. He had the car up on the ramps to do it and whilst there looked at all the bushes, drop links , usual suspects, etc. etc. and all he found were these loose stones.

Have you checked the bolts into the end of the drive shaft (14mm head under the dust cap in the centre of the hub) these have a habit of coming loose. Some people describe it as a crunch when setting off, accellerating and decellerating, on mine it's more of a knock. Tightenning these bolts gets rid of it for a few miles then they come loose again. They usually need stud locking back in. (or evidently replacing with xc90 bolts that lock somehow?)

Be carefull if you do try to tighten them as they are fairly small and if you shear the heads off you're in trouble!!

Can anyone with Vadis confirm the torque settings for these bolts or does it not give that sort of info? also can anyone confirm if the bolts on the XC are actually different (self locking) as my local specialist says they are not but I have read on here before that they are.

would have thought its your lower arm bushes
mine never knocked on 17 thors .ive just gone on to 18 and there i slight knocking and the car drifts around more tramlining etc.
got it up on the ramp and checked all the bushes and mountings needed are>top engine mount and lower control arm bushes(wishbone i call it)the bushes causing the problem you seem to have
order from partsforvolvos and fit them myself but ive got the use of a fully tooled up garage with 2 poster ramp etc

Correct! This is a (common) fault with the driveshaft to wheel hub interface. Volvo describe the fault as “axle ping” – but sounds more like a dull thud, knock or clunk, The tightening and/or adding of stud lock adhesive only partly solves the problem, as eventually the dull thud, knock or clunk returns.

The XC90 driveshaft end bolts are the Volvo prescribed fix for this. The difference is the XC90 bolts have a rubber cone that essentially dampens the movement between the hub and the driveshaft.
http://www.v70r.com/forums/uploads/1...5_108_8723.jpg
The torque setting for these bolts is 50Nm.

This is a very simple and easy fix:
You will need 2 pcs P/N 30714142
With the car on the ground remove the centre caps
Remove the bolt (14mm socket)
Clean off any corrosion or contamination
Inert the bolt and tighten to specified torque.
(No stud locking adhesive required – as already applied to the thread)
Refit the cap and you are in business!