Hi Corolland Masters,
Recently my old 1.8 1ZZ-FE VVT-i will develop continuous metallic noise when driving 80-110km/h. The noise might temporary eliminate if I release throttle and re-apply back (keeps regulating the throttle pressure). I found the power seems dropped after this noisy symptom surfacing. Mechanic suspected spark plug and V-belt issue, which after replaced still giving the same noise. I searched through some article and youtube, most people are showing rod knock noise or VVT-i noise on idle speed, but mine is showing noise only during driving under "part throttle". The youtube video on this link having exactly the same noise:
Any idea what's wrong before I visit another mechanic? Thank you.