High Oil Pressure?

1996 PONTIAC FIREBIRD
140,000 MILES • 6 CYL • 2WD • MANUAL
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MUZZLEBREAK
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Recently, as I was accelerating to enter the highway, I saw my oil pressure spike to over 100 psi. At cruising RPM the pressure remained high at about 90. Normal pressure for this engine is about 60. I changed the oil pressure sending unit. No change. Today I changed the oil pressure regulator valve. Still no change. Ideas? Thanks.
Mar 8, 2009 at 10:34 PM
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SQM
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Hello,

This could be due to a faulty oil pressure gauge.
Many of these model firebirds have issues with the gauge becoming inaccurate over time.

Try this testing to see if the gauge is faulty:
Disconnect the oil pressure connector from the sensor. Connect a 12 volt test light between the gauge lead and the ground. Turn the ignition to the on position.
If the light flashes then the instrument voltage regulator is working properly and the circuit is complete.
If the light stays lit, the instrument voltage regulator is defective and needs replacement.
If the light flashes but the gauge is not accurate then the gauge needs replacement.

You might also want to test the oil pressure by using a test gauge.

https://www.2carpros.com/articles/high-oil-pressure

I have attached diagrams for your reference.

Please let me know of any questions.
Thank you.
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Sep 20, 2021 at 10:39 AM