What did your mother used to say?
If you’re not part of the cure, you’re part of the problem.
That obviously goes for 0w20 in the 6.2.
GM aborting move to 0w-40
- Thread starter dbias
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If you’re not part of the cure, you’re part of the problem.
That obviously goes for 0w20 in the 6.2.
Here is additional info on the GM recall from a group of YouTubers.
That’s debating.
I didn't watch the entire thing but I noticed this comment:
"G.M. Insiders are saying that the affected cranks were all made in the two Mexican facilities. Not only were they not polished properly, they are out of dimension tolerance also. No oil change is going to help that. All knee jerk reactions from G.M. Trying to mitigate how much of a crisis it really is."
I'm not debating whether thick/thin is good or bad. I'm saying I don't think this is a viscosity issue here.
Yep.
Rather than wasting a full hour watching chuckleheads, you can watch one Canadian for less than 10 minutes skip to 4:00 and watch just a couple minutes and even get a better summary...........
Thanks that was good. Seems like a case closed at this point.
if it is a viscosity issue, the rod bearings is where it would show first.
Because of the elliptical orbit of the connecting rod, the bearings self pump better than main bearings.
What are the rod and main bearing clearances in the 6.2L?
I’m blaming the low viscosity 0w20 being insufficient for the journal diameters, bearing clearances, rpm and low oil pressure delivered by the variable oil pump when the rpm is suddenly increased.
Why the last reason? Because it takes a few seconds for the oil pump to respond and deliver higher oil pressure to the engine. At 6,000 rpm, that’s 100 revolutions per second that the engine is operating with low oil pressure especially at the bearings furthest away from the pump.
What does thin oil have to do with it? The bearing leakage rate is higher in the bearing cavity, so the oil is squeezed out faster than it can be replaced.
I wouldn’t be surprised if the “Mexican” crankshaft had another half a thou bearing clearance which reduced MOFT below the threshold for 0w20.
So what is your logical fallacy? Run with the crowd on consensus, or appeal to a higher authority like a secret informant?
If I owned one of these engines, I wouldn’t have put 0w20 in it to begin with.
And anyone using 0w20 should as a precaution, switch to xW40 asap.
What are the rod and main bearing clearances in the 6.2L?
I’m blaming the low viscosity 0w20 being insufficient for the journal diameters, bearing clearances, rpm and low oil pressure delivered by the variable oil pump when the rpm is suddenly increased.
Why the last reason? Because it takes a few seconds for the oil pump to respond and deliver higher oil pressure to the engine. At 6,000 rpm, that’s 100 revolutions per second that the engine is operating with low oil pressure especially at the bearings furthest away from the pump.
What does thin oil have to do with it? The bearing leakage rate is higher in the bearing cavity, so the oil is squeezed out faster than it can be replaced.
I wouldn’t be surprised if the “Mexican” crankshaft had another half a thou bearing clearance which reduced MOFT below the threshold for 0w20.
So what is your logical fallacy? Run with the crowd on consensus, or appeal to a higher authority like a secret informant?
If I owned one of these engines, I wouldn’t have put 0w20 in it to begin with.
And anyone using 0w20 should as a precaution, switch to xW40 asap.
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I contend these will fail on XW-40 as well, but maybe longer to much later.
Gretasurströmming
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I have stated a number of times here what I witness on my L83/L84 engines and don’t see how the 6.2L would be different … That so called VDP responds like a two stage and responds to throttle position. I have played with this on a backroad. Hit the gas and instantly max out on oil psi well before the RPM’s come on strong
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There was a comment about what kind of people made these parts in Mexico.
That’s a bit naive when you’d struggle to find a car company who does not get parts, complete rear ends, motors, transmissions, or even assembled cars from there - especially the Monterey region …
That’s a bit naive when you’d struggle to find a car company who does not get parts, complete rear ends, motors, transmissions, or even assembled cars from there - especially the Monterey region …
Thinking out loud:
You think the U.S. engine assy post assembly spin test would "see" undersized crank pins on the press/volum plot. Maybe they are O.O.T. oversized. Then again the spin test should see at least an interference in the spin-up torque reading, though it would likely not see a 0.0005" diametrical clearance (which will be << 0.0003" running).
Incoming QC sampling should have caught a batch of out of tol. cranks. Before that, the outsource factory automated tools would have caught it right away if programmed properly. Did GM Autodesk Fusion send some funky #'s? Was it a pandemic world crash and burn all around? Starting to smell like a big ball drop.
You think the U.S. engine assy post assembly spin test would "see" undersized crank pins on the press/volum plot. Maybe they are O.O.T. oversized. Then again the spin test should see at least an interference in the spin-up torque reading, though it would likely not see a 0.0005" diametrical clearance (which will be << 0.0003" running).
Incoming QC sampling should have caught a batch of out of tol. cranks. Before that, the outsource factory automated tools would have caught it right away if programmed properly. Did GM Autodesk Fusion send some funky #'s? Was it a pandemic world crash and burn all around? Starting to smell like a big ball drop.
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Nothing much here. A secret US auto worker bad mouths a Mexico based manufacturer. Yawn. Let’s get those cranks mic’d and compare them to the specs. Otherwise it’s just finger pointing.
I am sorta feeling what is the true root cause aka where is the beef??
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No, just 5W30
Or CAFE fines.
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