driving down the highway today, the car did the strangest thing. well, not that strange i recall having the same problem with the 96. i heard the warning beeps you get when the car decides theres something in your gauges that is in need of your attention. looked down, didnt notice anything. kept looking, and when i hit the brakes, oil pressure went down to below 40, easy. accelerated, and back up quite a bit. steady under steady acceleration, hit brakes and psi drops.

whats wrong with my car?

[ive noticed some things about the transmission lately too - revs high instead of accelerating in drive]

update and bump:

driving today, i paid close attention to it. went on a thirty minute drive, and near the end of it, oil pressure got shaky. any time i accelerated, pressure went up to around 70 psi. when i let off, dropped to about 40 psi. when i applied the brakes, dropped to below 40. under constant acceleration, the pressure bounced about 10 psi. when i got home, i left the engine running. put it in park, and it bounced about 10 psi. put it in neutral, accelerated, psi jumped.

whats wrong with my car? im going in for an oil change tomorrow, id like to tell them what to fix.

There'* nothing wrong with you car. It'* perfectly normal for you pressures to increase under load. 70 PSI is great, and just below 40 at ildle is excellent, too.

Wear is setting in on our 99. We get about 55 lbs. at highway speed and 35 at idle. I'm at 150,000 miles.

i know that my oil pressure moves quite a bit aswell, but i understand how scary the thought of maybe having an oil problem is.. if your still concerned about it, take a video and we can give you more feedback

ill probably do that after the oil change tomorrow.

i understand that psi will change, but its dropped to the point where i get the beep that says "somethings wrong with me, jeff"

You can increase your oil pressure 15psi by switching to MaxLife 10W-40 @ five quarts. You will also gain 5mpg. Use the AC Delco PF47 filter.

Oil pressure at idle is the problem in my eyes.

How long has it been since the last change?

about 2500 miles. and getting one today.

40 lbs of oil pressure at hot idle is a concern? That seems pretty solid to me.

Mmmm read this wrong. Sorry guys. (thought 10psi was hot idle )

I doubt the oil pressure is a problem at all.

What other things did you notice?
Transmission slip shouldn't do it without setting a check engine light.