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Old 01-28-2024, 02:47 PM   #1
iluvmy72
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Do oil pumps fluctuate?

1996 Burb 5.7

2007615 miles

Pressure gauge dip coming to stop or goes all the way down after leaving stop with Check Gauge” message.

Changed Oil pressure sending sensor.

Still same issue

Put in a can of sea foam and issue kinda stabilized a day to flush and problem only saw once after.

Had an oil change done the next day. Idle warm at around 40 on the gauge and at times goes to 30. Goes to above 40 on highway. Can oil pump be the issue?

Do oil pumps start to die or do they just die? Also was told this could be a stepper motor issue in the cluster.

There is no noise or rod knocking going on.

Will have a mechanic pressure test it in the next week.
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Old 02-11-2024, 09:13 PM   #2
DZL1
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Re: Do oil pumps fluctuate?

Interested to see results.
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Old 02-12-2024, 06:13 PM   #3
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Re: Do oil pumps fluctuate?

If it's still working fine after the oil change, I would suspect the old filter was either bad or clogged. If clogged, then something clogged it and you have an issue somewhere else. But filters collapse sometimes so maybe that's all it was.

On my 350, I get 55 psi cold, then down to 14 in idle in gear when fully warm and after driving. So it can fluctuate by RPM, temp, oil viscosity, etc.
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Old 02-12-2024, 06:16 PM   #4
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Re: Do oil pumps fluctuate?

Also, the gauges are not exact most times. I have a separate digital gauge wired to a sensor on the port next to the filter. If you're unsure about the actual pressure, hook it up to a mechanical gauge.
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Old 02-12-2024, 06:58 PM   #5
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Re: Do oil pumps fluctuate?

The OE oil pan on my 98 was slightly dented on the bottem, I imagine from a failed jack attempt or something stupid. Wasn't big though. Anyways, it was always about 60psi at startup in the winter. I recently put a new pan on it, and now its 80+psi [gauge pegged] at startup in the winter. Tells me it wasn't getting full oil feed to the pickup with that dent. Might be something like that with yours, easy to check.
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