Can you help me regain my confidence in my engine? 2019 Yukon 5.3

KARNUT · April 27

6 hours ago, Grumpy Bear said:

IF you mean Red Line as a brand he, Lake, and Terry Dyson both give it a big thumbs down. What's my data say?

Are you telling me I should surrender what anyone can see in the data to someone's notoriety? I don't do hero worship. Those two put their pants on one leg at a time just like you and I. I listen and I listen intently. I buy what has value and does not violate the physics of the larger scientific community. I have no trouble rejecting the garbage no matter who it comes from.

LISTEN to Lake carefully. He admits C.A.F.E., EPA and the API are in charge. What you do not seem to understand is that promoting that agenda is THIER BUISNESS. ALL his testing leans toward that light, just like a Sunflower.

Terry was more bold about it. VM's that had huge temporary shear values he saw as a "Feature" of the chemistry that allowed a 5W30 to be as fuel efficient as a 5W20. What it is, is additive companies 'marketing' CHEAP VII's as a tool for CAFE compliance. It's not a feature. It's a flaw and it's cheap to use and to promote. It will also not meet the specifications for the EURO C3 license which requires the oils minimum 150 C HTHS to be 3.5 cP and stay there. It requires the minimum 100 C HTHS to not fall below 9.3 cSt. This display below is an example of an SAE 5W30 made by Warren Oil for COSTCO. Look at the second yellow highlighted test result? ASTM D6616. This 5W30 has a HTHS of 6.9 cP at .800 gr/cm density. That's a 8.62 cSt 100 C viscosity or the equivalent of a modest *W20. (Thank you Anton Paar and an on line Cp to cSt calculator)

A 0W20 may not have any VII in it if the natural VI is high enough so when Lake is comparing one to the other he is actually testing the same OPERATIONAL viscosity. Do you understand that? Good.

Now, he is not 'wear' testing an oil like HPL No-VII Euro 5W300 which has a 100 C viscosity of 11.2 cSt both by ASTM D445 and ASTM 6616. It doesn't shear because there is nothing to shear. Both solidly in the upper half of the SAE spec and miles above the ability of the oil to meet the ILSAC GF-6 or 7 spec for 'fuel efficiency. I doubt you will ever see him test a ILSAC GF-7 5W30 verses a ACEA C3 5W30. Bad for the business of herding the sheepeople toward those products the OEM's, EPA are demanding.

If I might be so blunt...you are not looking for what's true. You are looking to be right and in that mindset you will hear none of this. I didn't write anything in this post you can't look up for yourself. But you would have to buy a few SAE papers.

Those three highlighted values show you the entire viscosity profile of Kirkland's Signature Series 5W30.

Top line is the SAE requirement ASTM D445 at 10.91 cSt

Second line is the 100 C HTHS, rarely publishied and shows the viscosity under dynamic high shear. 8.62 cSt (after conversion) [What the motor sees in the bearings] and it's OUT OF SPEC

Thrid line is the recovery viscosity or HTLS at 100 C at 9.4 cSt. In spec but after shear is reduced and that is the 'stay in grade' value.

So...Stay in grade doesn't mean what you are lead to believe. Hey! It's in spec!! Woohoo. Yea, not really. This physical behavior is why I choose 5W40 oils 90% of the time even for 0W20 applications. Lake did admit that these alternate viscosities are appropriate for the machine, just not approved by the law. Listen to everything.

Dude, chill. I was giving him another point of reference. You test your oil constantly, wonderful. You also drive like an old woman, also fine. I’ve also read that the engines are built specifically to use 0-20. I realize it’s for fuel mileage. I use 5-30 in my Odyssey. It sings its song on the highway in very hot weather. My test is to listen at start up for a rattle. No rattle good to go. I don’t know you. You do test make claims, fine. Lake Speed is known has a business that’s known. Just another point of reference. But a known one. One thing he can’t test is your right foot. That also comes into play. As does driving style and where you drive. There’s only one entity I hold up. The rest are just a point of reference.

Edited April 27 by KARNUT

OnTheReel · April 27

Grumps driving style, if anything, implies that there are even greater margins to gain by most more “typical” drivers who race from light to light.

When time and again @Grumpy Bear sees improvements from something like upping viscosity, it stands to reason someone who runs the 0w20 on the ragged edge pulling trailer uphill will see much much more. If they cared to actually try/ test like I have.

newdude · April 27

8 hours ago, PunchT37 said:

Hard to believe GM can’t or won’t correct machining problems after 3 years or so.

It happened though. That's the whole deal with the L87 engine issue on the T1s. Manufacturing defects of the cranks and con rods. Just like Toyota had for a year or two with their 3.4 Turbo in the new Tundra. Manufacturing defects.

Grumpy Bear · April 27

8 hours ago, KARNUT said:

I’ve also read that the engines are built specifically to use 0-20.

I'm plenty chill, thanks for caring.

What do you believe "Built Specifically" means? Think about it before you continue.

Go to the video and start about 45 seconds in and listen through 2 minutes 15 seconds. Lean in real hard at 1 minute 50 seconds and you will get your answer and it isn't what you believe it is. Lake and I are in Total agreement on this point.

These marketing types use the words "Built for" and "Tunned for" as interchangeable and as they do "Clearances" and Tolerances". They are steering people to a goal not the truth.

You have to listen to everything with more than your ears, you have to listen with discernment. Marketing is the craft of disarming discernment and the telling of artful lies.

Now about this below :crackup:

8 hours ago, KARNUT said:

You also drive like an old woman, also fine.

Like an old MAN sport, MAN. :rollin:

8 hours ago, OnTheReel said:

Grumps driving style, if anything, implies that there are even greater margins to gain by most more “typical” drivers who race from light to light.

When time and again @Grumpy Bear sees improvements from something like upping viscosity, it stands to reason someone who runs the 0w20 on the ragged edge pulling trailer uphill will see much much more. If they cared to actually try/ test like I have.

Bingo. Same reasoning GM uses a heavier grade for 'Track Day" oil call out than they do for "Daily Driver" mode in the same vehicle. It dumbfounds me that Joe Average can't cross that bridge during towing.

KARNUT · April 27

22 minutes ago, Grumpy Bear said:

I'm plenty chill, thanks for caring.

What do you believe "Built Specifically" means? Think about it before you continue.

Go to the video and start about 45 seconds in and listen through 2 minutes 15 seconds. Lean in real hard at 1 minute 50 seconds and you will get your answer and it isn't what you believe it is. Lake and I are in Total agreement on this point.

These marketing types use the words "Built for" and "Tunned for" as interchangeable and as they do "Clearances" and Tolerances". They are steering people to a goal not the truth.

You have to listen to everything with more than your ears, you have to listen with discernment. Marketing is the craft of disarming discernment and the telling of artful lies.

Now about this below

Like an old MAN sport, MAN.

Bingo. Same reasoning GM uses a heavier grade for 'Track Day" oil call out than they do for "Daily Driver" mode in the same vehicle. It dumbfounds me that Joe Average can't cross that bridge during towing.

Yeah, Yeah. I drive like an old man too. In a minivan mostly. And I like it. I was steering a person to do research. I never doubted your results. Not many has done more in field testing than me. The extreme side of testing with trucks and heavy equipment. Forty years worth. I put 1 million miles of pulling heavy equipment at 24K combined with one ton trucks. And at redline with diesel tractors powering our attachments. Am I an expert? No. Experience yes. 12 years retired things change. I research vehicles everyday. It’s my past time.

Edited April 27 by KARNUT

Atlas · April 27

On 4/26/2026 at 7:23 AM, BlaineBug said:

What do you think? I had hopes to keep this vehicle for at least 10-years but I feel as though my camshaft and lifter failure occurred VERY early. I inspect warranty claims on a daily basis and find that most of these lifter-related failures occur after 140,000 miles and beyond. I purchased my 2019 Yukon at Carmax in December 2019 with 34,000 miles on it - yes, that was a lot of miles for the first year, but it was a Hertz rental registered in Missouri. I would have assumed they did their oil changes on time. I found no signs of sludge or varnish. However I drove the vehicle over 50,000 miles without an issue at that point between December 2019 and November 2025.

The fact that yours is an ex-rental vehicle says a lot. Most rentals are redlined off the lot following a cold start. Lots of idling, lots of redlining, lots of short-cycling the engine, everything from test pilots to people who have a bone to pick with the rental company over cost/service, etc, etc.. The cars usually see maintenance from the lowest bidder, if it gets done on time at all...

Maybe that was a contributing factor, maybe not, but it would be a huge wildcard/unknown for me if it was my truck.

If you can't trust it, get rid of it. Buy something else or another one. It's not like these things are rare.

Life is too short.

Atlas · April 27

21 minutes ago, KARNUT said:

Not many has done more in field testing than me.

Except everyone else who has driven a truck and used heavy equipment throughout their careers. Bold claim, kNut.

newdude · April 27

7 minutes ago, Atlas said:

The fact that yours is an ex-rental vehicle says a lot. Most rentals are redlined off the lot following a cold start. Lots of idling, lots of redlining, lots of short-cycling the engine, everything from test pilots to people who have a bone to pick with the rental company over cost/service, etc, etc.. The cars usually see maintenance from the lowest bidder, if it gets done on time at all...

Maybe that was a contributing factor, maybe not, but it would be a huge wildcard/unknown for me if it was my truck.

We've seen pampered, pop-pop never went over 3000rpm trucks lunch cams in these.

KARNUT · April 27

1 minute ago, Atlas said:

Except everyone else who has driven a truck and used heavy equipment throughout their careers. Bold claim, kNut.

Just because I retired doesn’t mean my company isn’t still rocking. I took over for my father. My brother and nephew are still at it. The nephew is going to rock on and his son is in training. This isn’t small potatoes. Or a small company.

BlaineBug · April 27

1 minute ago, newdude said:

We've seen pampered, pop-pop never went over 3000rpm trucks lunch cams in these.

I remember an Escalade with a cam/lifter failure that I inspected, the heads were so clean they looked new...I forget what year it was, but it was of the 2017-2019 range.

Atlas · April 27

Just now, newdude said:

We've seen pampered, pop-pop never went over 3000rpm trucks lunch cams in these.

No doubt. But I also bet you've seen a bunch more with regular/scheduled maintenance and factory-recommended oil spec still chugging away at 100k.

Atlas · April 27

1 minute ago, KARNUT said:

Just because I retired doesn’t mean my company isn’t still rocking. I took over for my father. My brother and nephew are still at it. The nephew is going to rock on and his son is in training. This isn’t small potatoes. Or a small company.

But who asked?