Weird rattle under load at 2000rpm

[STP]

Mine was missing brake caliper springs on the front. Made an ungodly noise when the engine was allowed to labour around 1200 rpm, and also when driving over a mottled surface. They weren't included with the new brake kit so I didn't replace the rusty originals, but bought new ones recently and fitted them, the noise I had for months is gone. Silent.