Hi there,
There used to be a minor rattle on startup but since doing the cambelt its got worse which is why i thought valve clearances. However you don't notice it when idling but if you blip the throttle quickly its very pronounced, and now i noticed it the other night when driving at 50 with the window open so seems its getting worse. Its not as bad when warm but if you switch it off to pop into a shop it will do it when you come out.
I have bought the valve shim tool and some feeler gauges in readiness (and as its on 76k) but i think before that i'm going try running the engine with the aux belt off to rule out the alternator or AC compressor bearings.
I also had a quick look at the exhaust manifold tonight before tea and i can see at least one stud has sheared off. I will try putting some tissue paper near it tomorrow to see if there is a leak but i suspect this is the real issue...guessing because the engine was getting jacked up and down for the cambelt its made it worse, and it certainly corresponds to a video i have seen where that was the issue.
As a vague check I also put a screwdriver to the camcover and against my ear and that sounds very smooth so i don't think its anything internal at any rate..i.e. i've done all the cambelt/timing correctly.
I will try and get a video tomorrow but its exactly like this video @ 19 or 20 seconds in;
https://www.youtube.com/watch?v=E0ysC-OHie0