worth a read
I too was having cam chain rattle on start up sounded like a derv GTI , once warm it got quieter but I still had a noise similar to the tappets rattling
so last week after what seemed like a lifetime wait it went to my mate for a cam chain , variable timing unit and other bits needed to cure this its a revised part so you have to change the whole lot this came in at £670 part alone ,
this was changed cured the start up rattle but the hot running tappet noise was still there my mechanic traced the noise to the bottom left hand rear of the engine he'd already dropped the sump when doing the valve gear
when he looked for the noise he found this in the balance shaft unit
this is the balance shaft unit it also houses the oil pump , its driven by a chain from the front of the crank shaft
the sprocket drive is a damped type and was moving side to side and when removed look like this
the balancer shaft unit has no serviceable parts apart from the oil pump and is sold as a complete unit cost £1200 lucky my mate had a second hand unit that was good and is now on the car running quieter than its ever done
my car is a 55 plate 75k engine with a full service history , I drive it as it should be driven not hammered but not carried around
there are loads of posts on here about engine noise on here hopefully all these are not this , my mechanic is a VAG tech currently working in a local main dealers and he or them have never seen this before but he also added that they don't see many Mk5's in the dealers workshop either
anyone else had this problem with the sprocket drive
Rob