ZEA2IS250

Hi there, hope someone can help me identify the engine noise that I am hearing on my 2 gen is250 (2008). car has done 70.000 miles. It is a tapping noise that can be heard clearly when engine is still cold, but also when at operating temp, although not as loud. Noise is not present when engine is idling or when keeping the same speed on the road. It can only be heard under acceleration. Here is a link to the noise that I have recorded: https://www.dropbox.com/s/2be0tr0psvwqea8/Bil-1.mp3?dl=0

Is this normal or not?