I didn't want to re-hash the oil thing either... I was just a spectator too!
I have nastly lifter noise in my 1988 Audi 80 Quattro. I was using Castrol
10w-30 and even tried the dealer's additive to stop it (which didn't work.)
After I used Mobil 1 (10w-30) the noise went away!!! Actually, it's still
there at start-up and continues for the first minute, but after the lifter
pumps-up, the noise is gone!!! I've had great success with the 10w-30, but
if you're in a really cold area, maybe you might want to consider the 5w-30
at least until it gets warm enough to use the 10w-30.
1988 Audi 80 Quattro
1995.5 Isuzu Rodeo
1984 Ford Mustang SVO