My 92 300D 2.5 Turbo does it when I drive it hard, leaving for work in the morning its fine, 45 minute run on the highway and I get to work and it sounds like a sewing machines, have replaced all 10 lifters and done some oil treatment but no improvement. I have been using Quaker State 15w40 HDX fleet diesel oil.

Don't know what to do anymore, MB is recommending a valve job which is kind of a minor engine rebuild. The car has only 65000 miles!

If you changed the oil a few days ago, I think in your case its just bad oil that engine is not liking.

Good luck...

Atif