The effects of 5W30 through small passages
- Thread starter ARB1977
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Oil pressure will trend higher, in a linear fashion, with an increase in HTHS...in any given engine.
wemay
Site Donor 2023
On a cold winter Canadian (or any northern US state) morning, a 0W-20 will be thicker than a 5W-30 here in Miami. 5W-30 will work just fine where 0W-20 is recommended. And, conversely, the debris was not caused by the 0W-20 being too thin of an oil. Good video for looking at that engine up close.
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I wanted to see the piston oil squirters with debris lodged enough to plug them up, if only to know cause & effect for that section. No bueno.
To my basic understanding of how anything is machined in NA or EU and subsequently cleaned of swarf, the chance that residue from machining is the real cause of these failures is virtually nil. If the cleaning process was the problem, there would be so many failed engines that wouldn't even make it off the assembly line or the plant lot.
I bet it's too tight clearances within the engine either from design or operational too much heat causing distortion and warping sections of the rotating assembly. Too much heat from perhaps too much throttle before the engine is up to temp, with perhaps too little oil in the sump.
To my basic understanding of how anything is machined in NA or EU and subsequently cleaned of swarf, the chance that residue from machining is the real cause of these failures is virtually nil. If the cleaning process was the problem, there would be so many failed engines that wouldn't even make it off the assembly line or the plant lot.
I bet it's too tight clearances within the engine either from design or operational too much heat causing distortion and warping sections of the rotating assembly. Too much heat from perhaps too much throttle before the engine is up to temp, with perhaps too little oil in the sump.
This ^
For reference this Quaker State 0w-20 is 44 cSt at 40C and 8 cSt at 100C. That is a significant variation the engine must be able to tolerate even within grade.
https://www.shell-livedocs.com/data/published/en/b239c5ec-089c-4682-a211-934fa45d1bfc.pdf
OVERKILL
$100 Site Donor 2021
Exactly. Oils that might get into the hundreds of cP in Dallas will be thousands of cP in Winnipeg of Fairbanks.
In general a tighter bearing clearance is a good thing. You get more bearing capability and less sensitivity to viscosity. But "when a bearing becomes a filter" as someone drily posted before, things get sideways fast-- you have NO margin for error.
I think one key takeaway is that oil filtration levels that were acceptable 30 years ago probably aren't OK anymore. As the oil and engine start to more closely resemble hydraulic systems, they're going to need super efficient filtration closer to what hydraulic systems have.
I think one key takeaway is that oil filtration levels that were acceptable 30 years ago probably aren't OK anymore. As the oil and engine start to more closely resemble hydraulic systems, they're going to need super efficient filtration closer to what hydraulic systems have.
I haven't work on any Toyota engine but have seen pictures of the VVT-i on a 2AR-FE engine which is spec'd for 0W-20. The third single tiny hole (aside from the Mikey Mouse ones) is maybe one of the smallest. (images in the link below)
Stil, that same engine is spec'd for 5W-30 in Japan. So, that's what I'm currently using.
https://bobistheoilguy.com/forums/threads/0w-8-in-2026-toyota-prius.399814/page-4#post-7542552
OVERKILL
$100 Site Donor 2021
Which is interesting, because it has typically been the Japanese OEM's that have spec'd rock catcher filters, and Toyota is now doing it blindly for 10,000 mile OCI's, conditions under which, as @ZeeOSix has pointed out, are the least ideal to be running a low efficiency filter.
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Didn't watch the video, but I'm sure it's already been said, oil gets pushed through clearances as small as 0.0015". Those "small" oil passages don't matter. Even 0W-8 is thicker at startup/ambient temps than a 20W-50 is at operating temperature. If the passage size was a problem, no oil would pump through.
Bearing clearances have been about as tight as they can get for the last 50 years without making them overheat. My Coyote service manual says the main bearings can be as tight as 0.00038 inch per 1 inch of journal diameter, and the rods bearings as tight a 0.00053 in per 1 inch of journal diameter. That's half the clearance as the general rule of 0.001 inch per 1 inch of journal diameter. Go any tighter than that and MOFT thickness inside the bearing gets pretty hot, which in turn causes the real time viscosity in the MOFT to decrease even more from added shearing heat. Too tight of bearing clearance can overheat and smoke them pretty quickly.
The blue text is my summary of the clearance specs in the service manual.
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Positive displacement oil pumps are used in engines for a reason. 0W-20 is recommended because of CAFE. Engines in other countries specify a whole range of usable viscosity based on ambient temperature.
It even says it in most Toyota OMs.
What happened to the other thread already started with this video?
Certain new Toyota/Lexus models have reduced their OCI back to 5000 miles, and increased the grade to 0w-20 once again.
After all this I’ll switch to 5W30 or even 0W30. Going back to my OG Amsoil SS. I have two oil changes worth of 0W20 EP. Hopefully by then my Tundra will either have its engine replaced or their data says it won’t. So far no metal is present in the oil filter.
That's a good sign. I'm surprised Toyota didn't do that routinely for any of these engines that are suspect to this failure to catch ones eating themselves up inside.
f355spider
$50 Site Donor 2026
Not when both manufacturing plants use the exact same process for machining and cleaning the blocks.
People who have visited both plants claim that is the case here.
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