often, it is the very beginning of a head gasket leak, unfortunately. have you cleaned the egr circuit?
Total 330000km. Head gasket was replaced 30000km ago by professional. Its causing differend style rattling and shaking. New HG solved it. Also whole EGR system was cleaned. Im thinking now that the noise is coming from vvt-i.. And what I found it is normal in some situations for cold engine start. Im using mobil 1 0w20 oil and oil level is OK. No oil consumption on change interval, and also coolant level stays topped.
Does not sound or look like a head gasket yet... maybe your variable valve timing needs an oil change
Are there filters in the vvti solenoid and valuing systems? Similar issues occur on the Honda vvt system.
Now if im really trying to think, maybe it makes the same noise before last oil change I made. After that noise is gone. So last oil change was 8000km ago. Maybe time to change oils like @rjparker said. I will call problem solved and case closed. Thank you all.
