Go buy the two little o-rings that fit on the end of the oil filter cap shaft. Pull the cap and replace them -- the ones on there are rock hard and leaking, and the oil leaks down out of the tappets overnight.

The o-rings and synthetic oil cured the lifter noise on my 87 300D.

White smoke on startup is unburned fuel, in this case probably from flat intake tappets and hence "late and low lift" valve conditions. Goes away when the engine is reved up since the tappets fill.

White smoke at idle hot is water/coolant -- cracked head/blown gasket.

I assume the oil pressure is normal -- about 2 bar at idle?

If good oil and the new o-rings don't fix the noise, replace the tappets, they won't get any better by themselves.

Check out my posting on rough idle, too!

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!