New Engine Sound!

Had full engine overhaul (rebore, pistons, rings, head etc) plus recon injectors (new nozzles). Whilst out fitted straight through middle section so now only one silencer box. Runs wells but seems to be very noisy! Have adjusted tappets, twice and it is all timed fine. Seems to be a slight metallic clatter, but only when accelerating, so fine on tick over, Also seems to get better when engine warm after about 10 mins or so. Seems to be from top of engine towards rear (clutch end), Any suggestions? Could be its just a different sound to what I am used to or could it literally be new injectors popping as they should??!

Should have said, it's a 200 tdi

air filter mounts knackered? they can make a right racket

On my 200tdi disco it developed a really irritating rattle at about 55-60mph. Changed engine mounts and hunted hight and low for it. Eventually it turned out to be the screen wash bottle rattling off the bulkhead!!!

I think it may be diesel injector knock, will try and diagnose a bit more. Not sure why it should be though

Can sometimes get a metallic sound from exhuast heat shield near manifold, orr from exhaust manifold not having fully sealed on reassembly - usually more noticeable when accelerarting

After much searching and some useful threads here, I retarded the timing slightly using an 8mm pin. Knocking gone and drives lovely