Re: funny tapping from the engine at 2000rpm
my bet is the balance shaft belt tensioner, had loads of these at work, after fitting a brand new alfa balance shaft belt, once the car is up to temp the knocking starts, we thing at work, the belts are stretching once hot , causing the tensioner to slacken and knock off the end stops on it. after fitting another alfa belt it was the same, we replaced several tensionres and belts on one car (under warranty) but still the same. only after trying an aftermarket belt (QH) the noise went away.
remove the timing belt cover and have a look at the tensioner when its running