I have an 04 Rainier with the 5.3L V8, just rolled over 100k miles.
Just started having a very quick low oil pressure alarm and seems to be running a little lower then normal as well. Idle and low load (1500 rpm) will read around 30 or so (use to be right around 40) and occasionally it will skip down to 20ish (alarm message on dash) and go right back up.
I had a low reading on my 05 Bonneville SLE (3800 V6) and replaced the oil pressure switch to correct it.
Does this sound like a probable cause on the Rainier? Where is the oil pressure switch located at on the Rainier and how easy to change / fix?