Valve clearances, + buzzing sound underneath car

[EDW2000]

My 97 1'L is due a major service soon at 85k miles.

The timing chain is a bit rattly on start up but otherwise okay, is it worth inspecting it for tension, and is there any need to do the valve clearances (never been done before)?

Can the timing chain be done with engine in bay?

Also, something is rattling/buzzing very loud, seems like front right side, checked the exhaust manifold heatshield and that is okay. Maybe coming from under the wheel arch? Seems worse when turning right. Annoying.

 

[nissan boy]

It's possibly for the valves to be done but not worth it, probs not much wear anyways
The buzzing tried pressing on the bonnet, inner arch , heat shield while running may find out what it is
The timming chain, what's the service intervals and like you use?

 

[slayer3312]

to do the timing chain replacement u got to take the engine out as no room other wise

 

[slayer3312]

the chain on my 1.0L started to wear it way in to the metal of one of the guides and also bit was missing on it