Getting periodic radical clanging under the valve cover

[djmarch]

Started off quiet, like the tappets when I start my 2004 with only 70,000 miles after it sits a few hours. Now it clangs off and on after start. Comes and goes until it warms up. Have no noticeable lost power, but seems to be getting worse. Not familiar with these DOHV engines, but will pull the valve cover off this weekend. Just hopes it will last til then as it's my daily driver. Scrathing my head thinking on what it could be ?..Broken valve spring ? Loose rocker arm ?...But why does the clanging go away after it warms up ? As far as I can tell, after pulling the cover off, it sounds like its coming from one of the two cylinders on the right side.

Any suggestions on what it could be will be appreciated.

[Daox]

When have you last changed the oil?

[BCAveo]

Aveos are know for valve problems, especially the earlier models. The oil flows better when warm so that's why quiet then. An oil change might help as suggested above. Would probably be noisiest if car sits for a few days allowing the oil to fully drain down into the crankcase.

I don't think removing the valve cover will help much. Could try Valve-medic (by Gunk) if possibly facing an expensive repair. I don't like engine flush type products too much though.