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Oil Pressure


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Hi everyone,

 

I am new to the Silverado community and just purchased my 2015 Silverado Z71 4x4 Crew Cab w/ the 5.3L a few weeks ago.  I love the truck but a little concerned about the oil pressure.  I understand that these trucks require 0w20 oil and have a new two-stage oil pump which I am sure contributes to this, but after a long drive and letting the truck idle for an extended period of time, my oil pressure will drop all the way to 20 psi.  Is this normal for these trucks?

 

As info, the truck has 53,000 miles on it.

 

Thanks!

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Often times oil pressure is thought to be higher than it needs to be. 20 PSI may be what is required on your 5.3. May have to look that up to confirm. Every SBC i have built in the past was from 20-40 PSI fresh.

 

I remember when Cummins came out with the ISX in large semi trucks. I had people coming in because the oil pressure was lower than they felt comfortable. When looking up the spec minimum operating oil Pressure Hot was 9 PSI. But they did not have Hydraulic lifters, so that was ok.

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1 hour ago, jwood0507 said:

Hi everyone,

 

I am new to the Silverado community and just purchased my 2015 Silverado Z71 4x4 Crew Cab w/ the 5.3L a few weeks ago.  I love the truck but a little concerned about the oil pressure.  I understand that these trucks require 0w20 oil and have a new two-stage oil pump which I am sure contributes to this, but after a long drive and letting the truck idle for an extended period of time, my oil pressure will drop all the way to 20 psi.  Is this normal for these trucks?

 

As info, the truck has 53,000 miles on it.

 

Thanks!

Yup, your perfectly fine!  Once it's moving on light throttle it's 30-40psi from what the dang gauge says?  Take it with salt though the gauge?

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Mine acts the same way.  When everything is warmed up, at idle I'm just over 20psi on the gauge.  Driving around with steady throttle, I'm just over 40psi on the gauge.  Flooring it, it goes up to 60psi or so.

 

Like they said above, who knows how accurate the gauge is, but it sure is nice to see it move.  My old Nissan, it just stayed in the middle and never moved.

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20 at the low side is no cause for panic, especially at idle in warmer weather with this water oil we use.

You will notice it jump back up to 40 when accelerating normally. And even higher when really getting into it.

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So there is a bulletin some where that said something like 2psi per 1k rpm and our idle is 400-600 depending on temperature. So around 10psi at idle you need to worry. That said I hate the gauge on dash I can see 20 the 80 at wot. So I installed a better gauge that data logs and has set warnings and temp. Also I have the 8quarts as gm now calls for. Really 7g and additives.

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I don’t know what’s normal for these trucks. I just the other day hooked up my DashBoss from my ctsv to my truck and my oil psi at idle stays in the high 30’s like 38 at idle and I’ll hit 45 with moderate throttle. 20psi seems low to me but I’m sure other guys on here know way more than me about that sort of thing

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I asked this same question in the "Ask the GM Technician" section: The reply I got was that once up to full temperature the following measurements are minimum. He did not specify what oil temperature they call fully warmed up but it takes longer to warm the oil that it does the water. This is also with fresh oil I was informed today by a second source. 

 

22 PSI @ 1,000 rpm

30 PSI @ 2,000 rpm

33 PSI @ 3,000 rpm

 

Second stage turns on at 3,500 rpm but there isn't any pressure information for output. At least any anyone I've asked is sharing. 

 

The dash gauge is NOT even close to accurate. At idle my gauge says 30 psi but the ECU says 19-22. At 1,000 rpm my dash says 39 psi but the ECU says 24 psi. At WOT my gauge will be just under 80 psi but the ECU says roughly 50 psi. 

 

In the shop I'm told they have a mechanical test gauge that takes the place of the oil filter to test the pump fully. Doing mine at the next service interval. 

Edited by Grumpy Bear
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5 hours ago, Mikebtte said:

Often times oil pressure is thought to be higher than it needs to be. 20 PSI may be what is required on your 5.3. May have to look that up to confirm. Every SBC i have built in the past was from 20-40 PSI fresh.

 

I remember when Cummins came out with the ISX in large semi trucks. I had people coming in because the oil pressure was lower than they felt comfortable. When looking up the spec minimum operating oil Pressure Hot was 9 PSI. But they did not have Hydraulic lifters, so that was ok.

I noticed that on my ISX's, then when you hop in one of the Paccar MX trucks and hit the GO pedal, the oil pressure is so high it nearly maxes out the gauge. The ISX engines were garbage and had horrible driving attributes, revs fell off too quick. Most people were lucky to break 500,000km with one before dropping a liner. None of my guys can shift one until they spend a few days in it. Not like a Cat where anyone with half a brain can drive it smoothly. We have one of the new X15 Cummins and it is a lot nicer to shift/drive with than the outgoing ISX. Good to see some fellow big diesel guys around here. 

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