Need Some Help to Decifer This ticking Noise from Engine

[Crazecow]

 

hi guys here is the video taken. Cause I only got it this morning when engine is sufficiently cold. The noise is soft but try turning up the volume and you can hear a ticking noise in the background. Around 11sec mark after I rev up the engine and left go. Then you can hear a soft krrrr.....krrrr.... noise in the background. Its soft (sorry taking from my cell phone).

 

It doesn't appear to get louder or follow the engine RPM and it seems to disappeared after I rev the engine, and appear only when idling. It will disappear after a few min when the engine gets warmed.

 

I can't exactly pinpoint the location too. Doesn't seems to be from cylinder 1. Sounds like its from the throttle body area. Btw, I am not using stock idle valve. I am using a Bosch valve (not sure if thats the cause of the problem).

 

All I know is that it happens the next day I change my oil to Schaeffer Supreme 9000 5W40. I don't know if its the oil though. I also have a bottle of Liquimoly Ceratec additive added (using it for over a yr already thus can't be the additive causing problem now).

 

thanks for the help.