knocking from right rear area

[Bryan]

I've recently suffered from a knocking noise coming from the rear right area of my Fulvia S1 sport 1.3S when on left hand bends.My first thoughts were that it was contact between the transverse exhaust box but that looks ok. My next thought was the shock absorber so I removed the lower mounting bolt and the shock was hard to push upwards but returned easily as if it only relied on a spring. Is this normal or should the shocker be double acting? All bushes look ok and I can find nothing obviously loose. Does anyone have suggestions?

[Huib]

The shocks are probably single tube De Carbon high pressure gas shocks. There is a chamber inside filled with gas under high pressure. You might google on it. They work differently from the more standard twin tube hydraulic shocks. The De Carbon shocks are ideal for a Fulvia.

Did you check the shackle rubber at the top of the shackle?

[Bryan]

Thanks Huib. I didn't check the spring shackles so I will do that next

[Bryan]

I jacked up the rear and used a tyre lever under the wheel to try to provoke some movement in the shackles but I couldn't observe anything. Visual inspection looks ok. I've searched the web to find more info but I haven't been able to establish if the shocker should act when extending. Under compression it appears to be ok but the return is definitely soft. I plan to remove the bottom mounting on the other side to see if it's the same but maybe somebody can advise me before I crawl under the car again.

[Huib]

When you compress the shock and release it it extends again but at a much slower rate than when driving on a street. This only checks if the high pressure gas is still there preloading the hydraulic fluid. I never succeeded in moving it fast enough by hand to test the resistance of the hydraulic fluid through the small holes inside.

If you want to check if the shock causes the sound, why not take it (them) off?

[Andrea Nistri]

Are the 4 bushes of the antiroll bar OK? They are known to wear, Andrea

[Bryan]

If I compress it from the bottom it returns as if it is spring loaded but you are right, I need to remove it completely. Thanks.

[Bryan]

I did try to detect any movement but I'm not sure in which condition it should be free to move if there is any play. From what I tried I found no play.

[Huib]

And then drive the car without the shocks. Take it easy. Don't try motorway nor rush hour without shocks.

[racing]

Very easy to check it is to change the Shocks from left to thr right side and from right to left. If the noise change also the shock is the reason. This is a standard prozess if noise problems are coming up.
This kocking noise can be from cavitation depent from the lost of gaspresure
Regard Andreas