Hi, since i purchased this 1.4 TSI BLG Mk.5 GT GOLF as my first car, I've been having problems with this tapping noise, it's only audible from 800rpm til 2k rpm.
This is a list of parts i have replaced in the last 4 months of ownership:
>2x Camshaft adjustment control valve
>2x Camshaft adjuster
>Camshaft position sensor
>Tappets
>2x Sparkplugs
>HPFP
>Piston Rings
>Rod Bearings
>and a few other sensors
Plus manual cleaning of the MAF, intake, throttle body, valves and such, however none of these helped even slightly and now the car is running worse than ever, i've had piston chamber compression tests done and they came out fine, with only one piston being slightly affected, it's running at about 80% what it should be, also oil pressure tests came out fine, they also said the timing chain system is fine. Something interesting happened yesterday, when I took out the Camshaft adjustment control valve and started the engine without it, the tapping was barely audible while close to the engine with the bonnet up, but as soon as you revved it the tapping came back, that got me thinking if its something electrical rather than mechanic, so i took it to an electrician who checked the ECU and told me everything was fine. This car has truly done my head in and the mechanics are sick of seeing it, how should i go about fixing it?
Video of tapping noise:
