My car is exactly the same. 20 psi (as shown on the dash) is normal at idle when the car warms up on a very hot day, slightly above the 20 mark on a cooler day. Notice that the red warning area is around 15 psi.
The dash oil pressure meter in a Catera is a mixed blessing. On on hand, it gives you information that other cars don't have. On the downside, it makes owners (especially new owners) worry needlessly as they watch the needle go up and down with the RPM of the engine. There are dozens of threads on this forum with exactly the same question.
The Catera was my first car with an oil pressure gauge. When I first got the Catera over 15 years ago, I was so alarmed by the gyrations of the oil pressure gauge I took it into the dealer who said it was normal. On a cold start, my gauge can be pinned to the left of the 80 psi! But the engine ran fine for 15 1/2 years so far, and is as smooth and quiet as new.
NO, no warning lights or sound, so dropping to 20 psi at idle is normal????
Yes, especially when the oil is thoroughly warmed up - after a 10 mile drive or more. GM's "normal" oil pressure specs, warm, are 10 - 20 psi hot idle, 45 - 60 psi, 2000 rpm ("highway").
You guys are lucky in that you seem to have a pressure gauge that actually works - see my comment below...............
There is no need to use any sort of "oil conditioners" or additives - matter of fact, your owner's manual and GM Service bulletins specifically warn against it. Today's oils, especially the HD fleet and marine multigrades like Shell Rotella, Pennzoil LongLife, and the Chevron DELO variants, without extra additives, are just perfect for a flat-tappet engine.
^^^ hgqguy is right on the money for allowable oil pressure ranges.
^^^ investor74 is absolutely correct: Oil pressure gauges are supposed to move in response to normal pressure changes due to engine speeds. In my STS and in many other cars there is either only an idiot light or an oil pressure gauge that is so highly damped that it never moves: This is to prevent just the sort of needless return to a dealer because "My oil pressure gauge moves". Most "temperature gauges" are the same way: Practically no useful indication, only a needle stuck at 12 o'clock. The days of meaningful gauges in cars are gone forever.
For many, many years I raced some pretty sophisticated "sports cars": All the gauges moved all the time. Open my profile, surf through my 2 albums - lots of "stuff" for cars. Another infrequent poster in here, orconn, drove a Lamborghini (among other toys) for years - he watched gauges that moved, too...........
Hiya all! I know this post is about 4 months old so I hope by asking a question here I'm not necro-ing it lol
I just replaced my oil in my 01 catera, just the standard oil from the shop. Drove fine till today, the engine oil pressure light came on with a buzz and stayed on. now throughout this, the oil pressure remained at 60psi highway and when I pulled into work, idle around 20, so I did not see it drop into the red. Coming home from work, the light no longer light up and no more warnings. What do you think could have happened? should i be worried and have it checked out?
where do I find the check the oil sending unit - oil pressure unit ?
my car will not even turn over... new (good) battery, multimeter: 12v power to the starter and to the alternator...
power to the dashboard, lights, etc...
but when I rocker the key in the ignition to ON, all the needles move except the OIL/PSI. 20121207_155429.jpg