Knocking Noise from The Rear

[mdw78]

Hi,

My 1999 C4 has started making a knocking noise from the rear drivers side. It only does it over large bumps at low speeds. It almost sounds like the exhaust or heat shield rattling. I don't think it's the suspension because I got the OPC to check the suspension for play before the wheel alignment was done last week.

Does anyone have any ideas?

Thanks,

Mike

 

[bobsan]

drop link's come loose, just re tighten, happens quite often.

 

[mdw78]

Thanks for the fast feedback. If it's not too cold I'll give it a shot over the weekend.

Cheers,

Mike

 

[steveoz32]

Don't forget rear ARB bushes, 10 min job and 15.00 a pair from an OPC, can also cause knocks easily when the rubbers are worn.

The drop links attach to the ARB and it takes the strain and flex of the turrets, the worn rubbers can lead to the bar knocking on the metal clasps.

Oh also if the drop links are actuall worn they will also knock, the ball joint on the top or bottom wears during the vertical movement over 1000's of miles and the ball / bolt can knock against the housing. They aren't expensive, probably 20 each, but just be sure to soak in penetrating fluid if you have to replace, as you need an allen key in the middle of the bolt to stop the ball from spinning when undoing with a spanner and if it's too seized you will chew it up - it's then angle grinder time which is a real pain.

 

[Diesel130]

ORIGINAL: mdw78

Hi,

My 1999 C4 has started making a knocking noise from the rear drivers side. It only does it over large bumps at low speeds. It almost sounds like the exhaust or heat shield rattling. I don't think it's the suspension because I got the OPC to check the suspension for play before the wheel alignment was done last week.

Does anyone have any ideas?

Thanks,

Mike

Are you a golfer?... I had exactly that from the passenger side. Loud clonck only noticed over large bumps at low speed. Turned one of my golf balls had gone under the passenger seat from the rear when I braked heavily and was lodged in a golf-ball-size pocket under the seat, giving those symptoms!

 

[mdw78]

thanks steveoz32, I'll bare that in mind when I look over the rear suspension. If there is a problem that's good news that the parts are not expensive.

Also thanks to Diesel130, I'll have a poke around under the seats for loose objects (I'm not a golfer so doubt it will be a golf ball but you never know where those things will turn up).

I'll post an update when I find out the issue.

Thanks again everyone.