ST220 engine noise

[DA220]

Hi, I have recently bought a Mondeo ST220 as spares as repair, the engine runs fine apart from a loud ticking/knocking noise that I think is coming from the rear cylinder bank. I’ve had the valve/rocker cover off and had a look, the cams seem to be in good condition except one or two of the lobes have a slightly pitted area. The timing chain seems to be in good condition and isn’t slack. Below is a link to a video of the noise.

https://youtu.be/rLiWr9RUyE8

Does anyone have any idea what the noise might be? The car did have an oil leak so it may have been run low on oil by a previous owner. The noise is also always there, when the engine is cold and warm and at any revs .
Thanks

Edited by DA220 on Tuesday 14th November 20:43

[DA220]

Yeah it does seeem to be the valvetrain, I have seen the TSB and I have already tried removing the bearing caps and refitting which didn’t make any difference, would it be possible to replace the camshafts, rockers and lifters of that bank with second hand ones? Or is that something that isn’t recommended?

[DA220]

I’m not sure how much a complete cylinder head would be as there isn’t many for sale. I understand it isn’t a good idea to mix and match used cams, rockers and lifters, but would it be ok to get a complete set from another engine and replace them all in one go? I also removed the oil cap when the engine was running and whilst there was plenty of oil on the cams, there didn’t seem to be much pressure, I was expecting it to squirt out of the filler which if didn’t. Is this normal?
Thanks