Suzuki Grand Vitara/XL7 Oil pressure/bearings

Hello, I am in the process to learn how to
work on cars, and I was able to pick up 4
2002/04 Suzuki XL7’s (2.7L V6) since I chose
them to learn on. I have replaced chain
tensioner and stuff, but there is one thing that
worries me.
First I noticed it on my second suzuki with
160k miles, when I start the engine hot I can
hear what I believe to be a bearing knocking
for 1 second, and the oil pressure light can
flicker synced with the knock in extreme
cases. Sometimes it’s more pronounced,
sometimes less. Then I bought 2 more xl7’s
one with 190k and one with 260k, and they
both kinda do the same thing, but not as
much as the 160k, and not always. In the
160k one time it knocked 5 times and the oil
light flickered upon startup. In the 260k one
time the oil light stayed on 2-3 seconds upon
startup but no knock, but engine noisy.
Engine generally noisy for first 2 seconds on
hot start on all 3 cars. After 2 seconds they
run buttersmooth, except 260k is a bit louder
but no surprise there. But it’s louder then
160k but has less knocking problems at
startup. The fourth suzuki with 155k never
did that. The only reason i noticed was
because I could cross reference, anybody
else would probably not have noticed.
I figured it is normal to a certain extend since
all three do that, but I’m worried about 160k
since it has the least miles and does it the
most pronounced. After 1 second it sounds
really nice but I will never forget the knock-
knock-knock I got one time at hot start.
My guess is bearing clearances due to wear,
and when the oil is hot and thin and no
pressure it knocks for a second, until
pressure surpasses 5-10psi? I guess main
bearing but I really don’t know?
My problem is, I can’t really wrap my head
around how worried I should be, and what
exactly is the actual cause/reason this occurs
in the first place, and how severe it is - how
much time is left on the clock before failure,
and if the development can be countered.
I can’t find any information online to this
problem, except for vague statements about
other makes and models. It seems I have to
figure it all out between my suzukis. Reason
for my concern is, that 160k does it more
pronounced then 190k & 260k, therefore I
conclude that the issue can get worse (faster
or slower), and I wonder what happenes
when the issue gets too worse, and when
that will be (if ever?).
Does anyone have experience with those
2.7‘s? Especially regarding oilpump/oilpump
chain, malfunctioning oilpickup and main/rod
bearing clearances? Or generally have
information related to the problem I
described?

Thank you very much for reading this, I
appreciate it!

Max