Hey all, my 300D just started making some noise in the top end, I'm hoping my crappy video will aid in diagnostic. It started with a light "ting-ting-ting". Sounds almost like an injector nailing. I didn't really think anything of it until tonight I heard something that didn't sound quite right at a certain engine RPM. I could be hearing things where there is no issue, but I don't really fancy destroying the engine.

https://www.youtube.com/watch?v=EqqA3Ac8NFc

Starting at 0:10, you can hear the "rattle". It sounds like it's coming from under the valve cover near cylinder 4. Almost like a resonance or something. It can be heard on and off again from 0:17 - 0:24. The ting noise can be heard pretty clearly starting at 0:39.

Thoughts? Thanks in advance for the replies.

__________________
- Johnny

1990 300D 2.5L - 135k
1998 Jetta TDI - 257k
2005 E500 - 117k