* Just installed 8 new oil tubes on the left cylinder head of this 119.985 engine (about 105K miles) in a '97 E420 (210.072). The end of the fourth (from the front) oil tube was missing, allowing oil to escape. This is apparantly a common problem. Looked for the missing end-piece but could find it. The cam lobes and cam follower tops looked ok.
* The engine makes the same ticking noise now as it did before replacing the oil tubes. And from the same area, top of the cyl head around cyl 6.
* Here are my questions. Do the hydraulic elements lose their sealing ability quickly when there's a reduction/loss of oil pressure to the element (since there's still plenty of oil in the area, just not under pressure)? In the future, should I plan on arbitrarily replacing the cam followers adjacent to any leaking oil tubes? And last, could anything else be responsible for the localized ticking? Thanks.