Drop in oil pressure

[clandr1]

Is your oil pressure needle moving relative to throttle input/load?

Yes, it is. While driving, it is at or above 40 psi.

Do you know for sure, that the pressure sending unit functioning properly and that the pressure gauge in the cluster is indicating the correct pressure based on voltage received from the sending unit?

Yes, in May 2021 my oil pressure gauge spiked to 80 psi permanently. I tracked this down to the oil pressure sensor, and after replacement, it has been operating as expected since. I have no reason to believe the gauge is reporting inaccurate information.

20-25 psi at hot oil idle is normal. As long as it goes back up to 40+ psi over 2000 rpms.

Thanks, it may just be normal wear on a high mileage engine that is still above operating spec, just not as good/high as it used to be.

 

[Cbncanada]

Sea foam really isn't meant to be added to your oil. Just intake and fuel system. SF is primarily a fuel system drier comprised of mostly isopropyl alcohol..nothing else.

On the contrary. It is meant to go into your oil as well. It will clean your system and refresh seals etc. Read the label on the can.

 

[Matahoe]

On the contrary. It is meant to go into your oil as well. It will clean your system and refresh seals etc. Read the label on the can.

It's my opinion it won't work. Go ahead and put it in. It's your car. You do realize it's just isopropyl alcohol... No detergents or solvents. Pretty mild. SF was never meant to be used when flushing an engine. That prescription just ain't on the bottle.

 

[S33k3r]

I'm just going to place this right here: HOW TO ADD SEA FOAM MOTOR TREATMENT TO CRANKCASE OIL

 

[clandr1]

Updated the OP for a little more detail that PSI seems to be normal when the truck is moving, my main concern is with PSI at idle when the motor is hot.

I forgot to mention I used Liqui Moly motor oil flush in June 2021 without any change, so I'm not sure an engine flush is going to fix the low pressure.

 

[Mudsport96]

My Silverado runs 40 to 50ish at highway speeds and 20ish at idle, if i wind it out around 5500 to pass it will clear 60 psi. You are probably fine.

 

[Matahoe]

Make sure your using an ACDelco PF-61e or PF-46e filter. There are a few service bulletins regarding it. If that don't fix the issue then at least it's been ruled out...

 

[Matahoe]

Updated the OP for a little more detail that PSI seems to be normal when the truck is moving, my main concern is with PSI at idle when the motor is hot.

I forgot to mention I used Liqui Moly motor oil flush in June 2021 without any change, so I'm not sure an engine flush is going to fix the low pressure.

Seems like you've covered a bit already. My only remaining concern would be to check that the correct ACDelco PF-46 oil filter is being used. And also it seems per the owners manual that 5W-30 synthetic is the recommended grade of oil that covers a wide range of owners situations. Try that as well. If you got to this point you will want to get a oil pressure gauge for manual testing purposes.

 

[clandr1]

Seems like you've covered a bit already. My only remaining concern would be to check that the correct ACDelco PF-46 oil filter is being used. And also it seems per the owners manual that 5W-30 synthetic is the recommended grade of oil that covers a wide range of owners situations. Try that as well. If you got to this point you will want to get a oil pressure gauge for manual testing purposes.

Great point - I have used nothing but AC Delco PF46E filters for at least the last few years. Prior to that I used Wix, Mobil 1, or NAPA Gold so I've always used what I consider to be "good" oil filters, based on what I've read online.

Can you clarify your mention of the owner's manual calling for 5W-30? Maybe I wasn't detailed enough but I have used Mobil 1 High Mileage 5w-30 synthetic since 2011 or so - perhaps you were under the impression I wasn't using that type/weight oil.

 

[clandr1]

Based on the feedback in this thread, I think I'm just going to keep driving it as is with no changes. I've read online that minimum oil pressure spec per GM is 10 PSI per 1k RPM, and if that's truly the case maybe I shouldn't worry about it until it drops below that threshold.