Knocking

[Tom]

how can i find out if this is actually the problem??

Seconded - I have a similar issue.

 

[Makaveli160]

Mine did this on my 182, easy to sort, just wrap one layer of electrical tape round the silver 'U' catch and it takes the play out of it and stops the rattle.

^^ exactly, i find it works best if you have a long enough length to wrap completely around the 'U' latch and then the ends of the tape stick to the plastic boot trim, although if your opening and closing your boot alot you will need to reapply it so its taught (as it strecthes and goes inside the 'U').