Oil pressure concerns… (Page 2/2)
armos JUN 14, 01:51 AM

quote
Originally posted by theogre:
GM and Most Others say a Range of Pressure at All RPM Because Oil Pump installed can generate More Even At Idle and have a Regulator to Limit Final Pressure.


"All" RPM? Clearly there's a lower limit, I assume you mean some idle RPM. Pressure has to approach zero as RPM does the same.
Real oil pressure fluctuates significantly with temperature and RPM. I've not only seen this on the 2.8L, I've also seen it on the Ford 4.6L V8 and on a Quad-4. Many dash gauges will hide the variation but a real mechanical gauge will show it.
I would say it's normal to hit the 60psi limit when cold. You don't want to be running like that in normal driving but on cold start it's normal. This is essentially where you get the headroom to still have good pressure when hot.


quote
Low Pressure is a Problem. Pump itself and other parts can wear out. Many drive w/ Low Pressure for years while others leave you stranded on the highway at worse time possible w/o other warnings. But you can believe the myths saying is "Normal."


The question is how low is "low". The oil warning light turns on at 8PSI. If they wanted it to always be 30 in all conditions, I think the light would be set to turn on at ~20PSI, not 8.
theogre JUN 14, 12:00 PM

quote
Originally posted by armos:
"All" RPM? Clearly there's a lower limit, I assume you mean some idle RPM. Pressure has to approach zero as RPM does the same.
<Snip>
The question is how low is "low". The oil warning light turns on at 8PSI. If they wanted it to always be 30 in all conditions, I think the light would be set to turn on at ~20PSI, not 8.

No.
Read Actual Data From GM and Alldata... In Short:

V6, VIN-9, 30-45 PSIG
L4, VIN-R, 36-41 PSIG
At All RPM including @ Idle.

PSIG is Standard Gauge Reading. (PSIA w/ A = Absolute is what MAP sensor reads starting from Total Vacuum.)

If Really Cold and Outside of Temp Range for given Oil Grade per API info then maybe the Oil is thick and won't flow causing high pressure.
code:
Lowest expected  	Typical SAE grades for cars
outside temperature
0°C (32°F) 	 	5W-30, 10W-30, 10W-40, 20W-50
-18°C (0°F) 	 	5W-30, 10W-30, 10W-40
Below -18°C (0°F) 	5W-30
(Old table Doesn't include new 0w-20 or 0w-16)

Very Hot Engine Should Not Cause Significantly Low Pressure < ~ 25-27psi for VIN-9 V6.

Fiero and other Dash Gauges are Very Dumb and Follow every change from whatever Sender Immediately. Same for people saying Engine Temp Gauge bouncing like https://www.fiero.nl/forum/Forum2/HTML/146181.html currently.

Other vehicles often have BCM controlled gauges or other buffering to slow gauges so people don't panic cause fake problems for Dealers and others.

A dash gauge reads higher/lower often isn't a engine problem but wiring problem. You check w/ a real gauge connected to the engine directly and hopefully within above range.

Warning Light On < 10 PSI is a "Last Chance" Warning the Engine will die soon or now. Good when have old style OP Gauge Sender known to empty the oil pan, morons leave oil drain loose, etc.
While 84 Fiero and others have OP Switch to turn On a Warning Light... GT pod gauge just have extra light run by the gauge to add more warning because out of normal viewing angle. This Light will Lie for Same Reasons the Gauge Will Lie.
ninedriver JUL 18, 09:53 AM
Thanks for all the replies and information. I’m going to up the oil weight and note the changes across the rpm’s and loads. This is my fair weather fun car so I don’t put a great number of miles on it but I certainly want it right/dependable. If I need to tackle the bearings and oil pump, I’ll probably wait until the fall. Hopefully I’ll see some results with the increased oil weight in the mean time.