Noise from engine on 1999 Audi A4

Hello, I have a noise coming from the top, right side of the engine (as you are facing it). the electric fan works fine, the other fan can be easily stopped by hand. Timing belt was done and it's not rubbing. Sprockets look good.

2 answers
Its hard to guess without hearing the sound first hand could it be hydraulic lifter noise from the valve train? Does it make noise at half engine speed or go away after the engine is warmed up or reved up?
If it is lifter noise try using Risolene oil treatment it is low viscosity high detergency and may clean the lifter out after several oil changes.
I had this issue, could be timing chain. unfortunately, timing chain kit is £500 to replace!!!