i have a 2001 v8 ghia that appears to make a tapping noise as the engine is started and oil pumps up.
As the engine gets to operating temperature it then quietens down with the odd tick tick knock knock.

How can i stop this noise, i have added nulon lifter quiet but this has not done much.

Have only recently bought the car with 130,000km on it and has done very few km's in the last 2 years.

The car is in very good condition but i would like it to run quiet.

Is it an expensive process to clean or replace the lash adjusters and how do you get them out or where are they located?

I would consider a full engine oil flush before next change.. if it doesn't not improve after that consider other more expensive options.

Also what oil did you use?

used sell helix 15-40

maybe i could use a thicker or better oil

I used to run shell 15-40 and nulon worn engine treatment in my au v8, same symptoms as yours. I tried thicker oils, expensive oils but the nulon and shell seemed to work best

i had the same problem , so i put mobil 1 (5/50) in it and the noise never came back.

Strange isn't it... I put semi-synth in mine and it started to rattle at startup as you describe, so I went back to Castol Magnatec and its been quiet ever since...