Engine knock..

[Red Ranger]

Hey been sortin out my bro's s1 vn for the past couple of weeks and as of this morning out of the blue it has got a pretty serious knock happening,
Slight knock on start up, pretty un noticeable at idle, gets worse as revs increase..

I want to suss out all the simple an common things first as it is raining here and dont wanna strip the block down with so much moisture in the air..

Any ideas?
An yes i have searched first

 

[Red Ranger]

Just had to back it down the driveway to get one of the other cars out,
Noticed that the knock fades away a fair bit when its in gear hmmmmz
Oh its an auto btw

 

[lepht93]

harmonic balancer? check it for cracks/chunks missing

 

[Red Ranger]

Pull it to check it? Or would damage be externally visible?
No external damage, i even took the belt off to lesten load.. But kept knocking like johvo

 

[Red Ranger]

Hoping its not the bigend

 

[Red Ranger]

Ended up being the bigend, so we ripped the motor out an put a new one in, all good now hahaha been a long 3 day swap, bed time now