My 97 vtec sounds like a sewing machine in the morning and i have adjusted the valves a couple of times and it has not made a difference.As soon as it warms up it is quiet,but for the first ten minutes or so it sounds very loud and annoying.Anybody else have this problem? The car has 100,000 miles and runs great its just loud on start up.I have tried different additives and oils with no real results.Any Ideas?

 

That's perfectly normal. Most Honda 4-cylinders do this, as the metal expands the noise quiets down. Blame tight production tolerances.