Horrendous engine ticking noise when hot and idling
 

(see YouTube link below for an example of what I'm dealing with)
When ever my engine warms up and I leave it to idle for more that 30 seconds it starts making a horrendous ticking noise, almost sounds like the chain it hitting the top of the rocker cover, if anyone has any idea of what it could be or how to resolve it that would be great, thanks.

https://youtu.be/LZLm83RuNik

Its the VCT gear

If you cant replace it, the vct can be eliminated by swapping in an s13 intake cam gear and bolt but you lose a ton of bottom end. Wouldnt recommend it