Strange Engine Sound At 4000rpm

[-LiNkS-]

Am new to the site...

hey guys i had my GT starlet for a while now.......oil level always good....coolant level the same......no oil light or engine check light came one......but today i got a strange kind of knocking sound at 4000rpm from my engine while i was driving :ffs: ......my volt gauge was 14.3 vlts, wide-band was reading my usual readings.......engine temp was ok.....am not too sure if i am loosing power.....but the sound gets lil louder. when idling you don't he the knocking sound.....am still using my stock cams but i never herd they sound like that.....

I change my oil just last 3 weeks and had no remains in the oil in the sump....my engine was resently been rebuilt and forged over a year now....i change my oil every 3 month which is around 3000 km

I checked the fault code.....it was 14