C5 Suspension knock

chrisall · Post by **chrisall** » 11 Apr 2011, 21:47

Post number 2! No doubt I will have a few more to add as various faults, I mean features, of my C5 reveal themselves to me!

This one concerns the front suspension - imagine I go over a speed bump at about 20MPH, it's fine as I hit it, no noise & it goes over really smoothly, but it seems to clunk from underneath the front suspension / steering rack area as the wheels drop on the other side. It's as if the suspension is fine on compression but not on rebound.

It definitely isn't the underneath of the car hitting anything - it does the same on rough road surfaces when the wheels are unloaded.

I hope to get under and have a look for anything obviously lose / worn, but any suggestions welcome (other than drive slower!)

Cheers,
Chrisall

Citroenmad · Post by **Citroenmad** » 11 Apr 2011, 21:54

Would this clunk only occur when the front wheels are likely to be at their full travel? If so its the struts coming to the end of their downward travel.

However if its happening on smaller bumps where the suspension travel wont be used up then something is worn somewhere.

Drops link as common on C5s but they cause a rattling and not really over speed bumps.

timborob · Post by **timborob** » 11 Apr 2011, 23:26

That's a good Post.

My car does the same if you go too fast on short speed bumps,
I understand what you are saying as it feels like the whole car shakes and drops though you are not bottoming out.
If I go over longer speed humps of 4ft + in length at 20 mph then it doesn't happen.

It seems to be a feature of the C5 and its telling you to keep that speed down to 10 mph

Anyone else have ideas on it?

Citroenmad · Post by **Citroenmad** » 11 Apr 2011, 23:42

In a way this is not helped by the C5s inbuilt feature to protect its underbelly. When the C5 senses a series of large bumps and slow speeds it raises its suspension to increase ground clearance. This bringing the suspension closer to the full extended travel and so increases the likeliness of it running out of travel.

There are 4 speed bumps (quite smooth but tall ones) on the next road from here which I have to navigate every time I drive anywhere. I find if im not accelerating then there is no problems, but if i am the front of the car is raised more and so it bangs. The XMs under some circumstance do this too and they have far more travel than the C5s.

If it is this causing the banging then dont worry, if its something else however ....

timborob · Post by **timborob** » 11 Apr 2011, 23:47

Hi Chris,

My problem does seem what you are saying as only seems to bang on the small sharper speed humps.
I have noticed it does it too on rougher ground as Chrisall has said and potholes if I miss dodging them.

Citroenmad · Post by **Citroenmad** » 11 Apr 2011, 23:49

Hmm, it should not bang on smaller bumps. Can the bang/knock be felt as a vibration, perhaps through the steering wheel?

Some kind of damper or stopper should have been fitted to limit this bang on the downward travel, it seems to just come to the end of the strut movement and that it, there is no give.

timborob · Post by **timborob** » 12 Apr 2011, 00:00

I think I'm going to need someone to drive my C5 to see how it compares to others as can only gauge it against previous normal setup suspension systems which don't feel the same as this car.

I will get mine driven by Advantage Citroen dealer sometime by May/June and see if they comment on it in anyway

411514 · Post by **411514** » 12 Apr 2011, 12:51

It does sound as citroenmad said like droplinks, i had the same symptoms as you describe and iv just done them and its now perfect, you can check them pretty quickly just raise the car on the suspension and give each end of the droplink a good shake and youl probably feel some play in them, they are a common part to fail on a lot of citroens i believe, if the noise is troubling you then i would try changing the droplinks, eurocarparts do a pair including delivery for £24.80 and they are pretty straightforward to fit, hope you sort it

Citroenmad · Post by **Citroenmad** » 12 Apr 2011, 19:08

Also, if you get someone to rock the car from the side while you put your hand on the front drop link, you will feel the knocking through it if it has failed.

timborob · Post by **timborob** » 12 Apr 2011, 22:23

411514 wrote:It does sound as citroenmad said like droplinks, i had the same symptoms as you describe and iv just done them and its now perfect, you can check them pretty quickly just raise the car on the suspension and give each end of the droplink a good shake and youl probably feel some play in them, they are a common part to fail on a lot of Citroëns i believe, if the noise is troubling you then i would try changing the droplinks, eurocarparts do a pair including delivery for £24.80 and they are pretty straightforward to fit, hope you sort it

Ah, Thanks for the advice on this, I will have to get the Citroen Specialist to look into for me .

TBH I would have to get a Manual as as a novice and wouldn't really know
the droplinks to give them a shake

I could tell you most of the things under the bonnet.

timborob · Post by **timborob** » 12 Apr 2011, 22:24

Citroenmad wrote:Also, if you get someone to rock the car from the side while you put your hand on the front drop link, you will feel the knocking through it if it has failed.

Thanks too Chris

chrisall · Post by **chrisall** » 12 Apr 2011, 22:28

Thanks for the responses guys, I think I'll change the droplinks to start with as they are cheap and easy enough to do. If it still bangs on rebound I'll probably just consider it a feature! It is quite a loud clunk and seems equal on both sides - as has been mentioned it's as if the suspension has simply run out of downward travel.

Cheers,
Chrisall

411514 · Post by **411514** » 13 Apr 2011, 13:00

As a tip to changing them i would say make sure you have an impact wrench of some sort and a junior hacksaw with a few spare blades, if you can get the nuts of the end of the droplink then youre a better man than me, you'l probably have to saw the nut off, it might be worth giving them a squirt of plusgas the night before, sam.

Citroenmad · Post by **Citroenmad** » 13 Apr 2011, 17:58

Yep, I usually spray some form of penetrating fluid at the bolts on the drop links every day for a few days before I change them. Or you will round off the nut and have to grind them off.

However, only replace droplinks with genuine Citroen units, cheap ones last about 2 minutes, 3 if your lucky! Well ok, a little longer but not as good as the genuine ones.