Knocking sound passenger front N/S/F

[DSME]

Hello all, I have a DS5 and lately I hear a knocking sound from the passenger side front. Checked with a mechanic for obvious signs, we changed the wishbone, and anti roll bar links. The suspension leg is dry so it’s not leaking. 
 

any one have any idea what could be causing this? Because there is nothing clear to be seen. The bushes look ok. 
I have no idea what causes it.

[paul.h]

We had a 2015 C4 that developed a knock at the near side front when around 4 years old and 25k miles. The front strut did not have any signs of leaking. According to our local Citroen dealer parts dept. around this time Citroen had a bad batch of front struts that wear quickly so that the strut shaft develops play and knocks. Once I removed the strut the shaft had very obvious play as it could easily be moved sideways and make the knock but whilst still on the car was not obvious. I did not buy a new strut though until I had removed it to prove what was wrong, so then had to temporarily refit the old one but second time around I was a lot quicker at doing the job. The replacement strut was supposed to be improved and I replaced both sides, they were not too expensive from the Citroen dealer (£136 for 2 in 2019). I also replaced the top mounts but the original ones were still in good condition so could have been reused but I had a C3 that knocked and the top mounting was the cause. The DS5 is based on the C4 chassis so may well have the same parts and problem. To check a strut whilst still on the car, the chrome shaft needs pulling to see if the knock/any play can be found but this might not be easy.

[DSME]

12 hours ago, paul.h said:

We had a 2015 C4 that developed a knock at the near side front when around 4 years old and 25k miles. The front strut did not have any signs of leaking. According to our local Citroen dealer parts dept. around this time Citroen had a bad batch of front struts that wear quickly so that the strut shaft develops play and knocks. Once I removed the strut the shaft had very obvious play as it could easily be moved sideways and make the knock but whilst still on the car was not obvious. I did not buy a new strut though until I had removed it to prove what was wrong, so then had to temporarily refit the old one but second time around I was a lot quicker at doing the job. The replacement strut was supposed to be improved and I replaced both sides, they were not too expensive from the Citroen dealer (£136 for 2 in 2019). I also replaced the top mounts but the original ones were still in good condition so could have been reused but I had a C3 that knocked and the top mounting was the cause. The DS5 is based on the C4 chassis so may well have the same parts and problem. To check a strut whilst still on the car, the chrome shaft needs pulling to see if the knock/any play can be found but this might not be easy.

Hi.

Thank you for your response.

Can you help me to understand what you mean by pull the chrome shaft, sorry I know a little bit about cars but not too much. 

Also, I forgot to mention my car is the DS version of the DS5, I assume it’s the same strut etc?
 

I was just looking for the top mounts, and saw two separate components, top mounting & bearing. I assume I will need both?

Edited October 23, 2021 by DSME

[paul.h]

If you look at a picture of any strut, the bit I meant by chrome shaft is the long narrow shaft that goes in/out of the strut body as it goes over bumps and the top of it is held by a nut to the top mounting/bearing. On the car this is hidden by a rubber bellows and the coil spring. To test it for the wear that caused knocking on our car, the bellows needs moving out of the way so the shaft can be grabbed and moved/pulled/pushed around and to listen for the knock. I could not really detect any wear on our C4 though until the strut was off the car and the coil spring removed.

If you think strut wear could be your problem, I would see if anywhere has them in stock so can be obtained that day, then remove the one off your car to confirm the fault. Otherwise if your car is needed to be used you could end up doing what I did which was remove the strut and then have to put it back until I got the parts. I would not bother getting new top mounts/bearings unless on the first removal they seem faulty, for the C4 they cost £210 for 2 sides but since they were a special order (not normal stock) I could not return them so whilst not needed, I put them on anyway. On the C3 that needed a new top bearing the bearing fell apart as it was removed.

[DSME]

On 10/23/2021 at 1:41 PM, paul.h said:

If you look at a picture of any strut, the bit I meant by chrome shaft is the long narrow shaft that goes in/out of the strut body as it goes over bumps and the top of it is held by a nut to the top mounting/bearing. On the car this is hidden by a rubber bellows and the coil spring. To test it for the wear that caused knocking on our car, the bellows needs moving out of the way so the shaft can be grabbed and moved/pulled/pushed around and to listen for the knock. I could not really detect any wear on our C4 though until the strut was off the car and the coil spring removed.

If you think strut wear could be your problem, I would see if anywhere has them in stock so can be obtained that day, then remove the one off your car to confirm the fault. Otherwise if your car is needed to be used you could end up doing what I did which was remove the strut and then have to put it back until I got the parts. I would not bother getting new top mounts/bearings unless on the first removal they seem faulty, for the C4 they cost £210 for 2 sides but since they were a special order (not normal stock) I could not return them so whilst not needed, I put them on anyway. On the C3 that needed a new top bearing the bearing fell apart as it was removed.

Thank you, 

 

So I took out the strut and straightaway I saw that the mounting was broken, it has a small metal part in the centre, and that was completely broken off. 
 

The problem is, I had the replacement strut ready and not the top mount.

Next problem I faced was I went to collect a top mount, got it back and the bearing doesn’t fit snuggly inside, I guess because it’s not original. 
 

Citroen can’t deliver a new top mount until Monday but I need my car by Sunday as I’m driving abroad. 
 

Then my rubbish compression clamps won’t compress the spring enough to even get the coil back on the leg. Nightmare.

I’m now wondering what’s best to do, my car is out of action. 
 

Also, I couldn’t seem to remove the bellows, not sure how, but after seeing the top mount like that, I think the strut is not the issue. I guess I should remove the belows to test it anyway, but why doesn’t it seem to move?

I really don’t know what to do now.

[paul.h]

It does look as if the top mount is the problem. To compress the spring, a second set of spring compressors would help so that it can be partly compressed over as many coils as possible using 2 of them and then use one of the other compressors to fit over the full length of the spring once it is partly compressed and then the first ones put on can be adjusted to cover more coils. I am sure I had to do this on the C4 and on the second time I vaguely remember leaving the compressors on the spring whilst it was off the strut. With the spring off the bellows probably does not need removing to see if the chrome shaft can be moved sideways and make the knocking noise but I do not know why it can not be removed.

If you have a local garage they might compress the spring for a small fee but that goes against the idea of diy car maintenance to keep costs down.

[DSME]

10 hours ago, paul.h said:

It does look as if the top mount is the problem. To compress the spring, a second set of spring compressors would help so that it can be partly compressed over as many coils as possible using 2 of them and then use one of the other compressors to fit over the full length of the spring once it is partly compressed and then the first ones put on can be adjusted to cover more coils. I am sure I had to do this on the C4 and on the second time I vaguely remember leaving the compressors on the spring whilst it was off the strut. With the spring off the bellows probably does not need removing to see if the chrome shaft can be moved sideways and make the knocking noise but I do not know why it can not be removed.

If you have a local garage they might compress the spring for a small fee but that goes against the idea of diy car maintenance to keep costs down.

Thanks think I’ll get a second set of compressors then, it’s £20. I’d have to take a trip in a taxi with the leg and then pay just to get it compressed for me. I’d rather buy the compressors.

 

what do you think about the top mount, should I wait for the original?

the new one I have is ok, but the bearing from the old doesn’t seem a direct fit. It stays inside ok, but there is a plastic ring that goes around it and that has a little bit of space at the edges, allowing a little bit of movement inside.

 

I think that when the leg is put back together everything should be held firmly in place, but I’m not sure. The original part + bearing + (the part that fits against the top of the spring seem a better fit.

Edited October 29, 2021 by DSME

[paul.h]

I am not sure what I would do with the top mount. If fitting the new one risks damaging the bearing then you might need one of these as well as another mount. However, if the bearing is ok in the new mount then if it is used I would probably leave it in place. Maybe toss a coin, heads use original damaged mount, tails use new one for now.

[DSME]

10 hours ago, paul.h said:

I am not sure what I would do with the top mount. If fitting the new one risks damaging the bearing then you might need one of these as well as another mount. However, if the bearing is ok in the new mount then if it is used I would probably leave it in place. Maybe toss a coin, heads use original damaged mount, tails use new one for now.

All sorted now, the bearing fit in the new mount just fine. The issue was there was another ring (part of the bearing) that was still in the old mount. As it was quite greasy I couldn’t see the ring (it blended with the old mount) I thought I had taken everything out of the old one. 
 

I put some grease on the bearing put it all together, just took the car for a test drive and it’s perfect. No knocking noise, and no strange bearing noises so it’s all ok. 
 

Didn’t need a the suspension leg in the end, so I guess I’ve learnt maybe it’s best to buy a leg and top mount just encase next time.

 

One last question, when I put the leg back in and then started to put the nut on the top (above a rubber ring), it got tight, but then seemed to be endlessly turning, is it meant to stop at some point? Or is that because when it’s fully tightened it turns the thread along with it?

Edited October 29, 2021 by DSME

[paul.h]

It is always nice to end the day on some good news, well done for persevering.

To stop the shaft turning when tightening the nut, is there a hole in the end of the shaft to use an allen key or torx bit whilst using a deep ring spanner on the nut ? If there is a nut lower down on the shaft, make sure this does not undo if the shaft turns whilst tightening the top nut.

Did you need a second set of spring compressors to fit the spring back ?

I will not be on the forum for a few days.