Technical Knocking from rear end

[Lozzy08]

Hello guys! Now I have recently purchased a new punto sporting and have again aquired a rear end knock, but only when going over bumpy roads. As in it isn't a constant knock, if I go on the motorway you don't hear a thing.

However, I'm positive it isn't the shocks as they look in good condition and the car dosen't bounce around when pushed. I've also checked the radial arm bearing as that has been a problem for me in the past but they again look fine and the arm's have no play in them. I have however found something inside the spring that seem's to have fluid on it. I believe it is called the 'Damper' but not too sure. Here's some picture's to show what I'm on about.



In the above image, highlighted in red is the part I'm talking about. This picture is on the other side as I can't get a clear shot of the dodgy one due to the exhaust being in the way.





In this image is the fluid I can see on said part.



Here's another image to help

All comments are appreciated. Thanks.

 

[Ultimatum]

Thats looks just like residue, i dont think its be the problem, its sounds to familiar to my car lol

Have you checked the rear axle for any points of rust behind the exhaust, as it is not uncommon for the exhaust to hit the axle on puntos, to check get some people to jump up and down in the back seat and see if the exhaust clips it. If it does it will need moving further to the rear and up.

Hope that helps

 

[stu32uk]

I used to have a similar problem, a knocking noise could be heard whenever I went over a bump or crack in the road. Turned out to be a corroded bush, which had also caused the wheel to be slightly out of line. Seems to be a common problem unfortunately.

 

[QUiiNNY]

Just got back from my garage with the same knocking sound which almost sounds like a exhaust, and i've been told its the Radius Arm. You say you dont think it is but again well could be make sure you give your wheels a pull and see just "how" much play there is and there allignment.

 

[SamuraiDragon]

its prob the rear bushes. get em checked out. looking at the springs, it may be worth getting them replaced soon as well. looking very corroded. get a wire brush to them to see how badly they are corroded... if they are structurally sound, slap on some rust treatment and hammerite or something to at least slow the rusting down a little.

 

[Lozzy08]

Aye thanks for the replies. I'll check out the exhaust but I think it probably is the bushes too. At least I've done it before I guess haha. Thanks guy's