Knocking noise on my 1.4 Furio.

[BeckahJane]

Ive got a knocking noise on my 02 plate 1.4 Furio
Only kicks in at around 55mph and gets faster with acceleration.
If you go over 60mph the noise nearly all the time stops and if you go under 50/55mph there again is no noise.
What could this be?
My partner is a mechanic and we have looked all over the car and no sign of what could be causing the noise.
Has anyone had this before/heard of it??
Help! :(

[Lucas_VTR]

I had a friend who had a similar problem, couldnt see anything wrong! Believe it or not it was out of shape tyres!

[BeckahJane]

Haha - I have actually just worked out what the knocking noise was & it was nothing to do with the car - it was the aerial topper that I had put on was bouncing up and down off the roof whilst driving at higher speeds! :/ arghh how dumb (: