The metal (good) tubes were used up until m.y. 95' I think.
96' and newer used the cheezy plastic ones. Their end plugs pop out for no good reason. I have done new 99's with less than 10k
and 96's with over 150k. There seems to be no consistant failure
time or miles. However, when I do one, I do them all. I doesn't
make sense to chance a second failure when you allready have the engine apart.
As far as ticking and rattling on start up, there was a bullitin back in 9/92 for leaking drain-back valves on 119.970,971,972,974,and 975. This caused the oil gallies to the cam-adjusters to leak down and have to re-prime on start up. I have seen mostly 500E's with
this issue but also 400E's, 500SL's, 400SE/L and 500SE/L's have popped up from time to time. These were primarily 1992 and 1993 cars.
The valve is in the oil filter housing and requires removing the filter housing to replace.
The repair kit is PN #119 184 01 30.
you will also need a filter housing gasket and a filter.
The oil bridges (connector tubes) are PN #119 180 02 66.
Hope this helps.
P.s. If your V-8 rattles really bad on start-up, your chain is probably streched and slapping around in the timing case until the tensioner gets full oil pressure or you have a broken rail.
Either of these is a time-bomb. Get it checked out before it turns
into a $10,000.00 min repair job for a broken / jumped chain.