Engine Oil and Oil Pressure

swathdiver · June 3, 2019

Been concerned with the performance of regular Mobil 1 in the 5.3 LC9. Motor rattles on cold starts and she runs much better when 4K mile OCIs are followed versus 5K or 6K OCIs.

A few months ago I noticed that ACDelco was showing a new full synthetic engine oil when I ran my VIN on their page. https://parts-catalog.acdelco.com/catalog/catalog_search.php

It was listed for 4WD vehicles, which around the time mine was built, was for 4x4 Yukon XLs and Suburbans as they got the aluminum block engines. These engines see more expansion and contraction compared to iron block motors. Would also apply to XFEs and others as well.

Anyhow, when the time was drawing nigh for the next oil change, I set out to purchase 2 OCIs worth and ran into a couple of large minimum quantity issues. Finally found it 2 counties to the south and bought a case, three 5 quart bottles for $22 each.

I have NEVER seen the oil pressure this high across the board, ever. It appears to be a solid 4 psi higher than before when at a hot idle and up around 50 psi on a cold start when before it was just about 40. No more rattles on start up either. Prior to purchase, I compared specs and found that its viscosity numbers were higher than Mobil 1 regular full synthetic 5W30, about on par with the Group IV oils. The SDS says the oil is made by Phillips 66 Laboratories.

If anyone runs it, please also let us know your experiences with it. I'll be sending off a sample to Blackstone after the second oil change.

These are the part numbers:

1 Quart Bottles: 88865905 - 10-9234

5 Quart Bottles: 88865743 - 10-9147

Prior to this change, I had noticed lower oil pressure than normal and it was later determined to be caused by running the Mobil 1 M-212 long filter versus the PF63 and K&N HP2011. Switching off the M1 for the K&N resulted in about a 3 psi increase in oil pressure at hot idle. Now, with the AC Delco oil and the HP2011, hot idle oil pressure is about 29 psi (27-31).

Grumpy Bear · June 3, 2019

The pressures are from the dash gauge, right? About the same as mine now. I'll be watching this one sir.

swathdiver · June 5, 2019

On 6/3/2019 at 7:35 PM, Grumpy Bear said:

The pressures are from the dash gauge, right? About the same as mine now. I'll be watching this one sir.

Hi Marty,

The numbers are pulled from the Tech-2 which shows real numbers. Those observed readings were taken about 150 miles after the change, up to temperature and at night. Yesterday, with about 400 miles, the hot idle has dropped a little more but the observation was taken during the heat of the day too when it was 93 out. Still higher across the board and still delivers quiet start ups.

Does this chart jive with your numbers?

SierraHD17 · June 5, 2019

9 hours ago, swathdiver said:

Hi Marty,

The numbers are pulled from the Tech-2 which shows real numbers. Those observed readings were taken about 150 miles after the change, up to temperature and at night. Yesterday, with about 400 miles, the hot idle has dropped a little more but the observation was taken during the heat of the day too when it was 93 out. Still higher across the board and still delivers quiet start ups.

Does this chart jive with your numbers?

The numbers off the sending unit aren't much better. I pulled oil pressure on my 6.2 from the oil filter boss and had close to 20 psi of differential from there to the sender. Now there is loss from there to the sending unit but how much? I dunno. I swapped the sender and had no change on the truck itself. My reference is a $5000 Crystal IS33 deadweight I have calibrated annually so I believe what it says lol. I need to get an adapter to the threads on the valley cover and take my readings directly from there.

Grumpy Bear · June 6, 2019

13 hours ago, SierraHD17 said:

The numbers off the sending unit aren't much better. I pulled oil pressure on my 6.2 from the oil filter boss and had close to 20 psi of differential from there to the sender. Now there is loss from there to the sending unit but how much? I dunno. I swapped the sender and had no change on the truck itself. My reference is a $5000 Crystal IS33 deadweight I have calibrated annually so I believe what it says lol. I need to get an adapter to the threads on the valley cover and take my readings directly from there.

VLOM boss is 4-5 psi lower than the filter block on mine (hot). Have 44-48 hot idle and about 55 psi at 2200 rpm. Readings with the Snap-On version of the Tech Tool for the VLOM at the OBDII port and directly from a Snap-On oil filter adaptor mechanical gauge. Dash reads about 10 psi lower.

SierraHD17 · June 6, 2019

No Vlom on mine so that would be irrelevant to my truck. The pressure relief valve in the oil pan is downstream of my reading along with the cam phaser. Dash gauge is more or less useless lol.

Swathdiver would have the VLOM and the secondary pressure relief with a cam phaser so it's a lot of losses on his part over and above the normal lol.

swathdiver · June 6, 2019

4 hours ago, SierraHD17 said:

No Vlom on mine so that would be irrelevant to my truck. The pressure relief valve in the oil pan is downstream of my reading along with the cam phaser. Dash gauge is more or less useless lol.

Swathdiver would have the VLOM and the secondary pressure relief with a cam phaser so it's a lot of losses on his part over and above the normal lol.

No cam phaser on mine, the 2007-2009 5.3s did not have VVT. That was introduced in 2010. Mine does have the new VLOM and AFM has been turned off in the tune.

The oil pump for the aluminum Gen IV LS engines pumps 1.26 cubic inches per revolution, 33% more than the standard iron block pump. It has the yellow relief spring which is set for 33 psi versus 43 psi for the red spring. Melling sells this pump as the M365.

The Gen IV Hybrids have a variable displacement pump that uses 2 fewer horsepower to turn.

The Gen V LT engine oil pumps are different but not sure how.

SierraHD17 · June 6, 2019

Should have read under your name where it says 2009 lol.

Hmm... 33 psi must be where it starts to crack as they do not even remotely regulate at that. These should be able to peg the gauge or at least 70 psi or so. My own truck ( 2013 6.2) runs 65 psi Hot at 4000 rpm ( fuel cutoff in park) which from where I am measuring is true pump discharge pressure. Of course the sending unit says 48 psi or so at the same time lol. As far as I know my pump is the same unit the 5.3 uses anyway.

You have a secondary relief valve downstream of the pump that is supposed to be fully open at 55 psi... it looks like a little PSV you have on a home air compressor minus the keyring to manually open it lol.

The LS is a gerotor pump whereas the gen V is a vein style which is completely different. Plus the gen V has a solenoid controlled bypass that regulates pressure to around 40 psi below 3400 rpm.

swathdiver · June 7, 2019

23 hours ago, SierraHD17 said:

Should have read under your name where it says 2009 lol.

Hmm... 33 psi must be where it starts to crack as they do not even remotely regulate at that. These should be able to peg the gauge or at least 70 psi or so. My own truck ( 2013 6.2) runs 65 psi Hot at 4000 rpm ( fuel cutoff in park) which from where I am measuring is true pump discharge pressure. Of course the sending unit says 48 psi or so at the same time lol. As far as I know my pump is the same unit the 5.3 uses anyway.

You have a secondary relief valve downstream of the pump that is supposed to be fully open at 55 psi... it looks like a little PSV you have on a home air compressor minus the keyring to manually open it lol.

The LS is a gerotor pump whereas the gen V is a vein style which is completely different. Plus the gen V has a solenoid controlled bypass that regulates pressure to around 40 psi below 3400 rpm.

Yes, I think we both have the M365 with the yellow spring. Thanks for the extra information about the pressures and such!

SierraHD17 · June 7, 2019

I have a second 6.2 in the shop that was a warranty pullout for noise much like mine is making (pistons or wristpins) so now you have me curious as to what part number is in them Haha. I am going to rivet the valley towers closed on that one and remove that pressure relief as that "should" make a gen iv show oil pressure like the gen 3 engines do. Of course adding a cam to it and making some other changes before I plop it in the truck.

Grumpy Bear · June 8, 2019

On ‎6‎/‎6‎/‎2019 at 1:59 PM, SierraHD17 said:

The LS is a gerotor pump whereas the gen V is a vein style which is completely different. Plus the gen V has a solenoid controlled bypass that regulates pressure to around 40 psi below 3400 rpm.

I like windfall information. Thanks!