my car is a 1993-1.8 litre spec car-i disagree with the other posters who state that 190e cars have single row timing chain-mine has the dual row chain.
i know that some of the the earlier 190e models had a single row of chain associated with breakage with its resultant damage to the pistons/head,hence the need to replace the chain at about 100k miles.
the dual chains do last a longer time with regular oil/filter changes as per the maintenance schedule.
as a matter of co-incidence ,my car taps intemittently on cold starts and sometimes when warmed up.
it used to be a lot worse when my cooling fan was not working and the car used to run hot in traffic-the switch was replaced,the fan started working,car no longer ran extra hot in traffic and the tapping sound is less pronounced.
you could peep through the oil filler cap to diagnose whether you have a single or dual row chain
hope this helps.