C70: Knocking / banging sound from front left over bumps, bushes?

[SteveSarre]

Hi

On the left of this photo between 10 and 17 is a bracket that I think is welded to the steering rack body.

The bracket can break or the weld can break.

First time this happened, I paid for a refurbished rack to be fitted.

The next time, on another car, I paid £20 cash to the garage and they welded it while it was on the car. Still working fine.

Hope that helps,
Steve

[StatusRed]

Thanks for that Steve.

I just went and sprayed plusgas over the top of the strut mounts in the engine bay and the creaking seems to have gone BUT the loud thud sound as the passenger side goes over bumps is still present, the driver's side doesn't make this noise at all.

[ITSv40]

Originally Posted by StatusRed

Thanks for that Steve.

I just went and sprayed plusgas over the top of the strut mounts in the engine bay and the creaking seems to have gone BUT the loud thud sound as the passenger side goes over bumps is still present, the driver's side doesn't make this noise at all.

As you have recently had the driver's side suspension arm replaced and that side is silent, I would change the passenger side arm as most likely the culprit. Suspension components should be changed in pairs as if one side is worn the other side, although appearing sound, will be similarly worn.

[DaveNP]

Originally Posted by StatusRed

A problem I've had with my C70 for a while is thing banging / knocking sound as you go over bumps from the front left (passenger) side of the car. This goes away gradually as the car is driven then comes back after it's not been used for a day or two. The sound is quite noticeable but was checked over at it's MoT, deemed to be entirely safe (spring and strut are fine) it's just noise.

...

Cheers.

Originally Posted by ITSv40

As you have recently had the driver's side suspension arm replaced and that side is silent, I would change the passenger side arm as most likely the culprit. Suspension components should be changed in pairs as if one side is worn the other side, although appearing sound, will be similarly worn.

I wouldn't trust the MOT as a measure of wear and knocking in the suspension, just had my V70 MOTed and fully expected it to fail as I could see 1/4 inch of movement in the control arm bushes on the passenger side, it failed for a split gaiter on the steering rack and a dust cover on a drop link, the bushes were just an advisory and I get the feeling that was only because I told him before he tested it. The noise I got from that though was as I reversed out of a parking space on the opposite lock to what I drove in on.

[StatusRed]

I've jacked the car today and taken off the passenger front wheel to get a good look, I can't see anything glaringly obvious like a sheared droplink etc.. The only things that look remotely bad to me are the anti roll bar bushing and the shock looks like maybe it's too rusty and should be replaced? Control arm and droplinks actually look pretty good to me and the subframe bush on this side seems fine too.

Anyone else notice anything in this photos worth investigating?

What I think is bad:




Other photos:

[acshortt5]

Bit tricky looking at it on my phone but your droplink looks like it's bent near the bottom and the bottom cup section has separated from the bolt?
To check movement in the bushes get a crow bar and pry against stuff to see how much it moves/if the bushes basically just give way and you find a knocking sound.

[sam1]

just brainstorming...

the shock could be knackered inside... you say it is noisy after not being driven for a bit then quietens down... say the oil inside the shock all goes to the bottom when it sits... when it is driven again gets thrown around and quietens the shaft knocking about? the shocks look pretty old. not an expert by any means, just a thought...

[StatusRed]

Originally Posted by acshortt5

Bit tricky looking at it on my phone but your droplink looks like it's bent near the bottom and the bottom cup section has separated from the bolt?
To check movement in the bushes get a crow bar and pry against stuff to see how much it moves/if the bushes basically just give way and you find a knocking sound.

I think it's just the camera makes it look bent I definitely didn't notice it when my head was in the wheel arch, but possible I guess.

Originally Posted by sam1

just brainstorming...

the shock could be knackered inside... you say it is noisy after not being driven for a bit then quietens down... say the oil inside the shock all goes to the bottom when it sits... when it is driven again gets thrown around and quietens the shaft knocking about? the shocks look pretty old. not an expert by any means, just a thought...

Yeah that is a possibility. I think, because there's nothing glaringly obvious, I might order a polyurethane anti roll bar bushing kit off PartsforVolvo for £33, get them to fit it and also ask them to test drive it, listen for the sound and investigate.

When I first phoned them in the week I wanted them to quote me changing out all the subframe bushings etc but they didn't seem too keen, I think they're worried the bolts aren't going to come out and it would be a nightmare.

[Cookeh]

Tracking down suspension knocks is incredibly simple. You're able to take a wheel off and jack a car up, right? Do you also have something you can use as leverage, or even just your bare hands?

Jack it up, whip the wheel off, grab each of the suspension componments one by one and shake it around like a loon. If you cant replicate the noise, do the same with whatever lever you have to exert more force on it. Whatever you're rattling when the noise appears is your culprit.

[StatusRed]

Originally Posted by Cookeh

Tracking down suspension knocks is incredibly simple. You're able to take a wheel off and jack a car up, right? Do you also have something you can use as leverage, or even just your bare hands?

Jack it up, whip the wheel off, grab each of the suspension componments one by one and shake it around like a loon. If you cant replicate the noise, do the same with whatever lever you have to exert more force on it. Whatever you're rattling when the noise appears is your culprit.

I did try this by hand but not a lever - no movement in anything. This is what has got me thinking the shock and / or spring isn't working properly.