92 Nissan PU   2.4 Litre/146 cubic inch OHC , 4 cyl

hello folks,
First off, thanks to everyone who so graciously gave
me advice in a previous thread.

I got the truck back from the shop again.
This time they changed out the rod bearings, which they seemed
to think might have gone bad from water getting into the oil
when the timing chain *attacked* da motah!

Right after we picked it up, my wife noticed that the oil
light was coming on. Sure enough when I looked at it while idling
the oil light was on. The dip stick reported plenty oil however.

I called the mechanic and asked him if he thought there could
be a problem with the oil pump.

So I asked him what to expect if the the oil pump should happen
to stop working while driving. He said that motor would probably
make some kind of rattling sound. So I told my wife that if she
should see the oil light on and hear a rattling from the engine to
shut it down as soon as possible.

Well so far, the oil light hasn't come on again, knock on wood

But she did report to me that it came on when she was driving
at a fairly decent clip. She usually favors lower gears and keeps
the rpms up a bit more than I do when she drives, so it came
on when the rpm's were probably fairly high and continued to
stay on even when parked and idling.

Strangely enough, after I killed the motor and restarted,,
it never came on again after that for the entire
15 mile drive home.

She asked me what caused that.
I ventured a theory.
When the mechanics changed the rod bearings, they said that
there were plastic remnants from the timing chain guides
at the bottom of the oil pan. So, my theory was that perhaps
a piece of plastic got sucked up into the oil pump and
temporarily blocked oil flow until the oil pump eventually
chewed it up and spat it out.

Sound plausible? Or is there some sort of screen at
the oil intake tube that would prevent something like this
from happening?

Thanks
A very perplexed --Dave--