All the new modular motors make some kind of noise on start up.
They don't have that spiffy cast iron block to conceal internal noises.
Like i said, the nosiy V-8's tended to be 90 to 93' series.
By 94' the updated parts were phased into production.
Penz 15-40 is good oil too! We use it in older hi-mile motors
and they seem to operate quieter.