TD42T Intermittent Knock

Hello All, so the last month or so ive be chasing this god awful knock (added a video so you can have a listen), can here it quite clearly from the exhaust side of cylinder 5-6, i have had the sump off it not a week ago and have gone over all the big end bearings and inspected them which they all seemed fine, have compression tested (all came back between 500 - 530) the motor and leak down tested it which was all good, have replaced the turbo as it had blew all the seals out of it and was leaking oil quite bad, whilst replacing the turbo i inspected the exhaust manifold for any unwanted cracks or leaks and it was all fine (still factory exhaust manifold) the dump pipe on the exhaust did have a leak and have replaced with new gasket and has fixed that issue. replaced all the injectors and glowplugs to rule that issue out, i have put the stethoscope on injector 6 and it is extremely noisy compared to the rest. recently put a new radiator/waterpump and thermostat in it also as it had a leaky water pump because i let it sit for 6months.

any help or knowledge would be appreciated.

also late note, when cold the noise is not there, it will speed up with rpm https://youtube.com/shorts/7P7hDPRpPys?feature=share

https://youtube.com/shorts/7P7hDPRpPys?feature=share

Feels more like a rattle than a knock. Since you had the sump off already I suppose you checked the pickup tube as well right?

Does it goes away when you depress the clutch?

Can't hear any "god awful knock" in that video. In fact, it's quieter than mine.