Knocking noise underneath car

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My Name: Sbond13

Posts: 1
Joined: Fri May 17, 2013 12:46 pm



I have recently bought a C3 2002 plate and have noticed when I go along bumpy roads a knocking noise occurs underneath the car, its fine on smooth roads

Has anyone experience this before?

Cheers :D
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My Name: C3CAR

Posts: 2708
Joined: Wed May 04, 2011 10:01 am
Model: C3 2002-2005, Original shape model
Year: 2002 (02)
Engine Size: 1.4 (16v)
Fuel Type: Diesel
Mileage: 140000
Trim Level: Exclusive
Gearbox: Manual 5 speed
Engine name: DV4 16-valve diesel (90 PS)
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Hi Sbond13

Knocking noise from under the front of the car topic has something similar, although it could be a number of things from your description, it could also be the drop links as mentioned in the post above. Its quite easy to check them.

If it turns out the drop link is busted, change them in pairs for maximum safety, they are not expensive, you can pick up new CitroenC3 Drop Link Bars - on eBay (also called, anti-rollbar link or stabiliser bar link), but they do the same job of making a knocking sound under the car while traversing uneven surfaces.

A potential culprit for a knocking under the car on uneven roads:
Citroen C3 knocking noise - drop link
Citroen C3 knocking noise - drop link
Citroen C3 Drop Link Bar

or some worn out antiroll bar bushes make a knocking noise over uneven surfaces.

Other causes could be a missing or broken exhaust bracket. With the engine and exhaust cold, grab the exhaust pipe at the middle and give it a good tugging to see if it moves and makes a knocking sound.
My Name: jbz2079

Experienced Member
Posts: 51
Joined: Wed May 15, 2013 3:35 pm
Model: C3 2009-2013, New shape (A51)
Year: 2011 (11)
Engine Size: 1.6
Fuel Type: Diesel
Mileage: 75000
Trim Level: Exclusive
Gearbox: Manual 5 speed
DPF: Yes
Engine name: BlueHDi (100 PS)
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I agree with it possibly being the Anti-Roll bar links, but a word of warning.
My C5 had a chattery knock for a few months and I thought it was the links, as the car was comming up for it's MOT I thought, I'll leave that
and check the whole car over and fix those then.

When we did get the car over a pit, the knocking turned out to be the drivers side track rod end, (The Steering Knuckle )
By this time it was work to the point where it could have dropped off!

Always have a look, Don't presume, It's far safter. JBZ.
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