So as the title says and apologies for being vague.

 

I have a rather weird rattle with no consistent pattern. Sometimes it's there, sometimes it's not. It's definitely not there when the car is accelerating. It sounds like it's coming from NOT the top of the engine, as I cannot hear it as clear when I pop the bonnet open.

 

I will add a recording when it's night time to avoid daytime traffic noise but any ideas what I should focus on. I should add then initially few months back I heard a squeaking sound which has now stopped and turned into this.

So I got a garage to do some brief investigation on a ramp. They said sounds like the knocking is coming from gearbox most likely the dual mass fly wheel.

 

Assuming that is the case I guess I'd have to replace not just the fly wheel but other bits too. 

 

Can someone tell me all the bits that I should replace whilst the garage is in there