It didn't sound like the classic chain issue to me, but what is it?
In the last video 9 it sounds like the tapping doesn't increase with revs.
Here are a few facts.
- It only makes the tap between 1500-2200 rpm (at least it seems to disappear above that).
- There is plenty of oil in the engine.
- If I run for a few minutes at 3000+ rpm and then drop back down into that range the noise isn't there. If I run at low revs for a few minutes it returns.
- It doesn't seem to increase with revs (see video 9), but it difficult to say.
- It started after I did an oil change when I bought the car. (it had been standing for 12 months prior to this, but was fine when I test drove the car).
- The noise is definitely coming from the chain side of the engine.
https://www.youtube.com/watch?v=Cw-GnYx0u8g