zd30 crd cold start back off engine knock

[dilukabey]

Good day to everyone. My car YOM 2013 no egr by factory have an engine knock when decelarates from 2000 rpm or above. This is more noticeable after cold start. I have done diesel purge, fuel filter change, liqui moly Injector cleaning but non of them worked. This knock is coming from top of the engine. No fault codes with scanguage. Otherwise engine runs perfectly smooth. The video is attached below and appreciate any suggestions. Thanks alot 🙏

https://youtu.be/bgv-hNmHGUU