X-Trail - Clop-clop Noise from Engine Bay

[GX-Trailer]

 

Fellow X-Trailers,

In my T30 2007 2.5 petrol GX 4WD automatic,  I have a strange noise when I
am driving on a rough road surface, e.g. cobblestones. It appears to come from the
engine bay - a muffledl clopping noise, really just like a horse's hooves, that
does not seem to come from the engine itself and has a rhythm that is quite fast and
out of sync with the suspension movement, although, obviously, bad road
surfaces bring it on. It seems to be something loose, swinging like a pendulum,
but I can't see anything. I also don't suspect the engine mounts, as, on silky
smooth tarmac, I can jerkily accelerate and decelerate without causing the
noise. I'd be very grateful for any ideas on this mystery.

Cheers,
BRIAN