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Posted

Happy Easter!  Long time lurker first time poster.  I too experience the low oil pressure at idle (15-20 psi).  The truck 2019 Silverado LD 5.3 with 1,800 miles.  My wife drives a similar truck and it goes down as well.  I am interested to see if OP got any clarification from the dealer.

Posted

15-20psi hot idle would be completely normal. I think the dealer would just send you on your way.

Posted

Indeed you are correct, I decided to call the dealer today and they stated at operating temp; low idle; 15 psi on a mechanical gauge is acceptable.  Not to mention the dash gauge isn’t a precision instrument.  Thank you 

  • Thanks 1
  • 1 year later...
Posted

My 2 cents on this. 

Cold start ~35-40

Idle at 210F on a cold day ~20

Idle at 210F on a hot day ~18-20

Cruising down a 55mph HW ~40

Punching it from 0mph, range from 40 to 65 or almost 70

 

Always used Dexos approved 0W-20 and I live in SW Virginia

  • Like 2
Posted
On 2/2/2022 at 10:56 AM, SnakePlissken said:

Punching it from 0mph, range from 40 to 65 or almost 70

Maybe, like you are escaping from New York😬

  • 3 months later...
Posted

Afternoon everyone. 

 

I have a 2020 GMC Yukon 5.3... I was worried too when I saw my old pressure at about 18 when idle and 40 while driving at 55-60 mph. On the last oil change I added Lucas heby duty oil stabilizer and it did help a little. I mixed 1 quart of Lucas with 7 quarts of 0W-20 Mobil full synthetic and my oil pressure at idle is not about 20-23 psi and 44 while driving.. so for me, this helped picked up my oil pressure a bit. Cheers!

  • 2 months later...
Posted

So as my 17 5.3 with 140k gets older - I’m down to 20 - 22 psi at hot idle after an hour drive and 90-95 deg ambient. 
 

i run 5w30 and have since 70k. Truck is tuned and no AFM anymore. 
 

I don’t remember ever being below 30 psi in past summers. 
 

what could be going on? A lot of these posts are newer trucks and concerns. Mines probably around the halfway point of it’s lifetime. I need another 140-160k out of this thing. 
 

Does anyone have any additional  info on oil pressure at hot idle as these trucks get older?  My oil pump still does it’s self check and hit 60-65 psi over 4K rpm’s. Driving on the highway it still runs at 40 psi. 
 

thoughts?

 

any issues with oil pumps?  
 

I need to send out an oil analysis again at the next change. The first time I did I had high lead content but I think that was from a shitty gas station I was frequenting and getting my 89 required for the tune. It was also throwing cat efficiency codes which have since stopped since switching gas stations. 
 

thoughts?

Posted
14 hours ago, CamGTP said:

I see no issues at all. I see 20-25psi on my truck with 118,000 miles.

This. 👍

 

7-10 psi at a hot idle is all you really need, and 40psi cruising is fine.  Bearing clearance does open up with mileage, potentially dropping pressure slightly.  If the oil you're using has viscosity thickeners (to keep the -30 at operating temp), those additives deplete over time, leading to less viscosity and pressure.  Fuel dilution from weeping HPFP/injector(s) would do the same.  Pressure is also the pressure at the sensor, not the bearings; oil flow is what lubricates and cools bearing surfaces, not pressure.  High pressure could mean that the bearings are being starved of oil, which is potentially worse.  If a UOA shows fine, don't worry about it.

Posted
21 hours ago, DeePa said:

So as my 17 5.3 with 140k gets older - I’m down to 20 - 22 psi at hot idle after an hour drive and 90-95 deg ambient. 
 

i run 5w30 and have since 70k. Truck is tuned and no AFM anymore. 
 

I don’t remember ever being below 30 psi in past summers. 
 

what could be going on? A lot of these posts are newer trucks and concerns. Mines probably around the halfway point of it’s lifetime. I need another 140-160k out of this thing. 
 

Does anyone have any additional  info on oil pressure at hot idle as these trucks get older?  My oil pump still does it’s self check and hit 60-65 psi over 4K rpm’s. Driving on the highway it still runs at 40 psi. 
 

thoughts?

 

any issues with oil pumps?  
 

I need to send out an oil analysis again at the next change. The first time I did I had high lead content but I think that was from a shitty gas station I was frequenting and getting my 89 required for the tune. It was also throwing cat efficiency codes which have since stopped since switching gas stations. 
 

thoughts?

Lead is bearing material. What was the number? Get another UOA at the next change. How many miles are you running that oil?

 

As the miles rack up on an oil change, fuel dilution can thin the oil out causing lower pressures and premature wear.

 

I ran quite a few UOAs on mine when it was younger. I know from those that a standard oil (such as the 0W20 from the drum that the dealer uses) is toast by 4,500 or so miles in my city heavy and short trip drive cycle. Could I stretch it to 6k or 7,500 with an amsoil filter and boutique oil, sure, but that doubles the cost of the oil change and I have to add to cost of a UOA on to of that. There's no way I'd run any oil that far without a UOA every change. Now that the truck only gets just under 10k miles a year it's just cheaper and easier to get it changed at 4k; no UOA needed every change, cheap, and simple... and I know the motor is being protected.

 

Posted

The oil (5w30 full syn) had life left when I would change it at 6000 miles. This truck has never gone over the oil life monitor and never past 7500 miles between changes. The oil analysis said it still has another 1-2k miles when I changed it at 6000. 
 

I’m hoping the lead content was from that shitty gas station that would cause my truck to throw car efficiency codes. Blackstone said they see high lead ppm when people use octane boosters. I’m thinking the gas station was doing something stupid to make their 93. 
 

they also said our bearings are aluminum so the lead is likely from octane booster or leaded fuel
 

 

C32D3CA7-A077-4BF1-9370-854B2E3FA118.png

Posted

Another note. This oil is fresh with about 80 pct on the OLM wine the truck is dipping to 20-25 psi. 
 

I’m really hoping it’s just the heat. I see what everyone is saying about 10 psi per k rpm’s but my truck always hot idles at 35-40 psi up until about 120k

Posted (edited)

I’m no expert but the low flashpoint and fuel in oil shows some

fuel dilution, which would lower pressure. Viscosity numbers are at the low end of the range. 

Edited by 16LT4

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