I put my 89 WS6 with an LB9 TPI in storage last fall.

I got it out about 3 weeks ago...drove it for a few days before I got around to changing the oil. I noticed it seems like my oil pressure is lower than it used to be (car sat for 6 months...can't hardly remember what it used to be.

After a fresh oil change, 15W-50 Mobil 1 synthetic (I like the heavy stuff in the summer, I go 10w30 in the fall/winter/spring), my oil pressure still never goes above 30. Sometimes, at idle, it goes as low as about 15.

The pressure goes up as rpm goes up, but only until the rpm gets to about 1000. Then it levels off just below 30. I think (not sure) it used to go down to about 25, idling, in drive, and would go up to 45 as rpms went up.

It's got 151k miles on the motor, so it's no spring chicken, but still, shouldn't it be higher?

If my pressure is lower just because the car's starting to reach that age, wouldn't it still go up as the rpm increases? like up to 45-ish?

Or is it possible the oil pump is wearing out? or maybe crap has collected on the pump pickup screen?

for the time being, I'm still driving it, just taking it easy.

please let me hear your suggestions.

 

You seem to be ok to me. A good rule of thumb is 10psi for every 1000 rpms.

 

I think that's a good rule of thumb, but mine never gets over 30...usually right below, and if the engine is a good and warm, sometimes it's 25...doesn't matter if it's 2000rpm or 4500rpm.

Isn't that odd that it doesn't go any higher?

My last camaro with a v8 would go from 30 at idle to 45 at 2000+ rpm... isn't that a little more where my oil press should be?

 

Mine when i first start it up in the morning will go to around 35. thats the highest it goes to. then after everything gets up to normal temp it stays around 25 at idle. when i bring the RPM's up it will go to 30psi.

about 2 month's ago it would drop then go up wasnt very consistant. then it would drop to 2 psi, then spring back up to 25 or so...

I was about to pull the oil pan off and buy a new pump. then i talked to the guy at the shop...

he said always start with the cheap stuff and spend your way up to the more expenisive stuff....

for me it was a 12 dollar oil sending unit! thats what you might need!

 

Before I ever got highly concerned about a low oil pressure indication, I'd verify the accuracy of the oil pressure sender with a mechanical gauge. The factory installed instruments aren't that accurate, nor reliable after 17 years.