slayer_taunu

i just got an 88 GTA L98. when the engine is cold, the oil pressure is right around 45 at idle, maybe goes up a tad when accelerating. once the engine warms up, it will be just under the 30 psi mark when cruising at the highway, just over 30psi when accelerating, and down to like 15 when idle at a stop. the motor sounds healthy, but since the symptoms are consistent, i'm ruling out a bad guage.

i just did a search and some people suggested bad bearings... i'm hoping this is not the case since the motor seems rather healthy overall. even with 144,600 miles on it, the oil stays brown throughout the life of the oil change.

Apeiron

What you describe isn't low oil pressure.

True

Low oil pressure is much lower than that - that's lower than many of our cars, but still normal pressure. I've seen the rule of thumb around 10psi per 1000rpm, but the specs are lower than that on our engines.

You'll know low oil pressure when you get it (I just had some issues that attributed to low oil pressure... I need a new engine now)

slayer_taunu

hmm.... ok, just seems low to me, cuz my firehawk runs a lot higher. i just figured the L98 would run at 30 cruising and 45 under acceleration. 15 at a stop just seems very low to me... but if you guys say its normal, i guess i just gotta get used to a different engine.

Red Devil

Oils will 'thin out' as they get hotter, that's the difference you see when the motor warms up. While it isn't as high as I'm used to, it still seems fine.

Do you use a magnet on your oil filter? I'd grab an old hdd magnet and put it on the oil filter then cut it open at the next oil change and see what you find.

sofakingdom

iTrader: (1)

Very illogical. There is no good reason for doing that.

The gauge sending unit fails frequently in these cars, which of course will make the gauge read wrong. On the other hand, the gauge itself rarely goes bad, and the oil pump virtually NEVER does, unless it quits working altogether.

Try just swapping the sender out ($15, 5 minutes) and see if it's any different. If it's not, then either you don't have the stock oil pump in it any more, but rather a non-performance one; or your bearing clearances are excesive (worn out, needs rebuild).

jamessr

Also if you jut got the car, do a complete tune up. Know for sure what ytpe oil and weight you have in there. I like syn oils but they are rather thin. I had to get used of that myself. But do an oil change

five7kid

iTrader: (14)

I agree, do an oil change, but synthetic oils aren't any thinner than petroleum-based oils for the same viscosity rating at the rated temperatures. In fact, a quality synthetic is likely to be thicker at high engine temps than a petroleum-based oil - but even that is painting with too broad a brush, so let's just say that we aren't going to go around saying synthetic is thinner or thicker than petroleum-based oils, okay?

I also ditto the oil pressure gage error comments.

slayer_taunu

ok... i was ruling out the gauge because the results were consistent... but if you're saying they could be consistently off, then its worth investigating

Quick_Trans_Am

iTrader: (2)

That seems to be a common misconception about synthetics. I never noticed a pressure drop in My old L98 with a synthetic.

slayer_taunu

i did an oil change this weekend with penzoil 10w30 and a napa filter (which was longer than the 454 that was in there). now my oil pressure is even lower, and even went down into the red when i was parking at work today

i'm really hoping you guys are right about that oil pressure sender theory. i'm gonna order one today from o'reilly's.

True

Good luck with that. In the red = bad if it's not the sensor... I know, looking for a new engine for my car

Keep us informed, though.

slayer_taunu

when i did the oil change, i found out that the car has a magnetic drain plug. it didnt look like much, but when i wiped the magnet clean with a paper towel, there was some metal powder, a few fine metal filings and one larger fragment maybe about half the size of an ant (for lack of a better comparison). all this metal was grey in color.

slayer_taunu

the sender fixed it! i am so relieved, you guys can only imagine. i coulda swore 88 only had one sender, but there is one for the gauge and one for the 'light'. both of mine were seeping oil from the electrical connectors. i was gonna replace both, but the one for the light appears to use some special socket to remove, so i didnt feel like dealing with it yet. i'm more concerned about the gauge than the light.

i just went for a cruise, and once it was warmed up, the lowest it got to at a stop was what i perceive to be 25psi (a little more than halfway between the '15' and 30 marks)

thanks to everyone who gave me advice on this.