Oil pressure fluctuations at steady hwy speed and rpm. Ok?

[olliec420]

That’s a lifter knock - usually caused by bleed down in a lifter until it gets oil pressure again. If it makes the same noise every time you start it, it’s likely telling you that it’s time to replace it.

As to your oil pressure fluctuations, we’re all chasing a ghost until you get a mechanical gauge on that thing and ride around with it for a while. Could just as easily be an electrical/indication problem as a mechanical one but I can’t think of anything mechanical that would cause a fluctuation like that except for the pickup tube o-ring.

Makes sense. It doesn't after it hasn't been running for a while. Been doing it since I got it almost 30k miles ago so Im gonna let it ride for now.

The fluctuations have been going on since I got it and I have the paper work from the previous owner. When he took it in for engine rebuild from the oil consumption problem damage in 2013 or 14 or whatever, on the tech notes it says "customer noticed oil pressure gauge/needle fluctuations bounces" so it has been doing it for a decade+. I guess if there was gonna be damage from that it would have happened by now.

Im gonna put my scanner on it one day when Im driving long haul and when it starts doing it look at the scanner numbers and see. Will report back with results. Not to fix necessarily but in case anyone else needs it in the future.

 

[Geotrash]

Makes sense. It doesn't after it hasn't been running for a while. Been doing it since I got it almost 30k miles ago so Im gonna let it ride for now.

The fluctuations have been going on since I got it and I have the paper work from the previous owner. When he took it in for engine rebuild from the oil consumption problem damage in 2013 or 14 or whatever, on the tech notes it says "customer noticed oil pressure gauge/needle fluctuations bounces" so it has been doing it for a decade+. I guess if there was gonna be damage from that it would have happened by now.

Im gonna put my scanner on it one day when Im driving long haul and when it starts doing it look at the scanner numbers and see. Will report back with results. Not to fix necessarily but in case anyone else needs it in the future.

Yep, that makes sense. Then again, if there’s a wiring issue with the sending circuit, you’ll probably see the same readings on the scanner. But if it’s an indicator problem on the dash, then you’ll have your smoking gun.

 

[olliec420]

So I had a chance to check it with the scanner. Same on there. This is a couple days after an oil change. Fresh oil, fresh Delco PF48e filter. New o-ring, sensor, screen, galley plug, rear main seal, pressure relief value in oil pan, new deflector. All OEM parts. There is nothing visually wrong with the wiring. Well to heck with it, we'll see how it is after I delete AFM and turn up the power... one day.