Low oil pressure (15 psi) !!

[Lucchini]

     Hello, I have a brand new 2018 GMC Sierra SLT Z71 8 speed Crew Cab with the 5.3 engine. I know this has been discussed before, but I haven’t heard anybody say this low of oil pressure

(15 psi) at idle, stopped, in gear, after driving for about at least 30 minutes. Yes, I freaked out the first time I noticed it when the truck only had about 250 miles on it. It now has a little over 2000miles on it. When driving at speed of about 45 miles an hour it’s about 35ish psi pressure which I think is ok, and all other speeds it seems ok. It’s the hot idle (about 600 RPM)while stopped and in gear low oil pressure that has been bugging me ever since I first saw it. It only goes this low after driving for at least 30 40 minutes in warm 85* weather. I know about the two stage oil pump but this just seems low.

        Can anybody please tell me if their trucks run this low of pressure stopped, idling, and in gear, after completely being warmed up? It will put my mind at ease if others have the same results. Even pics of the gauge.

        Thank you,  Steve

 

 

[1SLOW1500]

Your good. But what oil weight you have?
Bulletin states that is fine.

Sent from my SM-N960U using Tapatalk

[KARNUT]

Most vehicles will have lower oil pressure in gear warmed up. If it was a stick you could get it down lower by engaging the clutch a bit. There’s a light that would come on if it got to low.


Sent from my iPhone using Tapatalk

[Lucchini]

It takes 8 quarts of the 0w20 wt oil which I know is thin.

Just getting this low on a brand new 2018 Sierra seems crazy as when the engine gets older, with miles on it, it will probably go lower..

Never had warning messages thou.

I know the dealer will tell me it’s normal until the warning message appears..

Anybody out there actually have oil pressure that gets this low?

So I should have nothing to worry about?

 BTW Thank you so much for your replies so far.

[Black02Silverado]

It is possible that the one oil pressure sensor that is on your vehicle is one that it's settings are reading at the lower side of average if that makes sense.  

[Lucchini]

 That could be.....

 The way I look at it if other people are getting this low of readings in these conditions, I should be good at the end of the day, I would think. 

[dougwtx]

My 2018 CC w/ 5.3 w/ 6sp trans does the same at various intervals.  Does not seem to matter if at idle or on highway.  Voltmeter also will dip low too but never had any warning lights/messages.  I have nearly 30k miles on mine now.

[DirtyAndy]

My 2018 CC w/ 5.3 w/ 6sp trans does the same at various intervals.  Does not seem to matter if at idle or on highway.  Voltmeter also will dip low too but never had any warning lights/messages.  I have nearly 30k miles on mine now.

Voltmeter dipping low is normal. GM thought it’d be cool to cause a panic doing this. It’s to prevent overcharging of the battery.

As far as oil pressure, looks ok to me. I’ll drive mine and get back to you. Pretty sure mine’s in a similar spot.

[mikedeezxxx]

My oil pressure is all over the place in certain conditions. Especially when the transmission shifts. 2016 Silverado Z71 Crew Cab 5.3L 6spd


Sent from my iPhone using Tapatalk

[Lucchini]

 DirtyAndy, it would be great if you got back to me on this.  Problem is you have to drive it for over 30 to 40 minutes to get the readings that low, as far as how mine is. 

 

Thank you guys for all these great replies. So you guys are actually getting as low as around 15 pounds PSI according to the lines on the gauge in the dash?

 The more people that chime in on these low oil pressure’s of about 15 PSi,  on this model year, I think, will make a lot of us feel better that it’s very likely normal .  I would’ve been OK  in the first place, if it was a little above 20 psi at the lowest reading .  All my other previous trucks, never went below around 30 psi stopped, at idle, in gear, after a long drive. 

 The more people that chime in, give us a better idea of how these new trucks really are or what to expect...

   

[Lucchini]

Mike,  in my own past experience having the oil pressure jump up-and-down as you’re on the gas and through shifting of the transmission is perfectly normal with any model year in my experience. 

[Paintor]

In the old days, 12 volts was sent to alternator to kick on charging system when key turned on. Resulted in overcharging of batteries. PCM now cycles alternator on and off to keep from boiling the battery off.

 

0 weight oil in Cali in hot temps getting low oil pressure....no fear. 

 

You can get a 5.3 with 20k miles from a crashed truck on Ebay for $2k. Keep trusting GM and just drive it. Insufficient Oil Pressure= AFM lifter failures via the Melling Bulletin from last year. They make the collapsible lifters for 4 cylinder shut down.

 

https://www.melling.com/wp-content/uploads/2018/03/Melling-tech-bulletin-on-GM-LS-Deactivation-Lifter-Issues-3.1.18-1.pdf

 

Read what Melling says oil pressure is supposed to be.

 

 

 

Edited June 23, 2019 by Paintor

[mikedeezxxx]

Mike,  in my own past experience having the oil pressure jump up-and-down as you’re on the gas and through shifting of the transmission is perfectly normal with any model year in my experience. 

Yeah thanks. I’m not worried about it. Funny thing is that I didnt mention that my oil pressure actually always goes up, never down. A little different than the OP’s situation.


Sent from my iPhone using Tapatalk

[Jacoby]

15psi is too low. I wouldn’t feel comfortable driving it. 

 

Hot idle mine hovers in the low 30’s and cruising I see 50+ psi. 

[79Mercy]

My 2018 5.3 will drop to 15 psi at hot idle after it gets good and hot, usually after a run on the highway in FL heat.  Im assuming its normal operation considering how thin the oil is required to be.