Disco 2 Engine Sound Worry

Ok, I'm hoping I'm not going to regret asking this question, but is my engine ok?

Always starts immediately, pulls ok under load, doesn't produce loads of smoke of any colour and when it's under load or coasting in gear with no throttle input the engine is really quiet, however, when I'm trundling along in gear with minimal throttle input, the engine sounds like a bag of broken spanners!!

Is it just me, or is this normal?

manual or auto

Ooh crap, I knew I'd forgotten something.
It's a manual

no noise on start up or shut down,no smoke when this occurs?

Quiet at startup, but a bit shuddery at shutdown. Nothing more than any other diesel I've had.

FWIW it's done 93k mikes

check front damper ,could be dual mass either will show by getting worse

You're a legend, thanks