Whats wrong with my car?

I have got a 2001 Ford Fiesta Freestyle with the 1.25 zetec-s engine in but under a certain speed and over rough roads there is a knocking sort of noise coming from the centre or rear of the car, its hard to pin point where it comes from. But it only knocks under 30mph on rough roads, get above 30mph and it dont knock at all, but i have checked it all over and the shocks are fine no signs of wheeping from any of them, everything feels tight and firm and nothing does not move as it should the anti-roll bar bushes are perfect. So im at a lose of what it could be, any ideas on what it might be?|||drop link ends - you will not notice the play if the car is at standstill. about a tenner per side for parts.

Very common problem in lots of cars. The symptoms you describe are classic.



Please be aware I could be talking rubbish having never seen a mk5 fiesta up close.|||It could be something as simply as your hatch is loose and rattles, but it could still be your shocks/struts. There is only suppose to be one bounce per jounce. Even if they are still firm and look good they can still be bad.|||Have you checked your Camshaft? that could be fuked as what happened in my mums (your future mum-in-law) old ford escort.|||try upgrading your gas see if that would work. (if it sound like little pepbles) It works only in the center knocking noise. If that dosent work have it check out.|||Check your exhaust hanger where it goes over your rear end.|||are the rubber exhaust mounts okay? could be rattling