I'm not clicking on it because to answer your question, no engine failure rates, at least discussed on this forum, are almost negligible.

 

Interesting that he's recommending a different weight oil. I'm having a hard time believing Toyota missed the mark on something so basic as proper ring gap....

 

I wouldn't say that exactly, this is also the same company who botched the cylinder head torque spec on the 7M engines.

 

It's also interesting that Toyota changed the part number for the pistons as of September 2024... makes you wonder what might have changed.

 

If interested, he has another video where he discusses his oil choices.
I may pursue testing with other viscosities... just because every time I change my 0W20, it reeks of fuel, which makes me suspect there's decent amount of fuel dilution.

 

I would like the last 14 minutes and 16 seconds of my life back please. Get outta town with this "mega-blowby" baloney; it just reeks of pseudoscientific fear mongering.

Excessive blow-by does not cause preigniton unless you're talking tablespoons of oil being drawn through the rings with each stroke and causing the effective compression ratio to skyrocket. What would end up happening with excessive blow-by is you'd get a lot of oil consumption plus fuel dilution in the oil, and eventually you'd lose oil film strength to the point where your bearings get to know their other halves really well and start knocking each other up. For the record, my GRC burns no oil and I have not smelled any fuel when checking the oil level or at oil changes. Sample size of 1 and all, but the video's sample size of "30 or so" isn't exactly a 95% confidence level either.

The piston he showed off did seem like the top piston gap was excessive though it's hard to say without seeing it inside a bore. --Side note, this is the first time I've seen a piston from this engine and my goodness that's an absolute unit of a top compression ring. It is by far the beefiest OEM piston ring I've ever seen outside of a diesel engine.-- The piston also doesn't appear to have the characteristic "scorching" below the oil control ring that comes from excessive blow-by, so I'm skeptical at that claim as well. It's hard to tell from the static shots if the speckles in the crown are actually from detonation pitting or just dust, but that would be where my money is on the actual failure mode. These engines, being high boost small displacement, are sensitive to LSPI (low speed pre ignition), which happens at low RPM and high boost, and is largely solved by staying out of boost below 2000 RPM. Using API SP oils (which are specifically formulated to help suppress LSPI) and the boost map limiting low RPM boost do a lot to help prevent this as well, but it boils down mostly to user error in the end.

With the roughly 20,000 GR Yaris and Corollas on the road combined, even if there were hundreds of owners that have blown up their engines, it's still basically a rounding error. This isn't nearly on the same scale as every other Tundra blowing up. The engine failure examples the video provided are also ridiculous; the first one being a literal WRC Yaris that's blown up (news flash: race cars blow up sometimes) and the second being that one guy who's had his warranty denied after his car caught on fire (which, yeah, no shit. Hard to warranty a melted pile of scrap; that's what insurance is for) where the only objectionable thing about the whole outcome was that bullshit 85 mph excuse Toyota gave about why his warranty was being denied.

Re-ringing the engine as a preventative measure is absolutely insane as a recommendation. What is this, a WRX STI?

I cringed at the recommendation of 5W30 oil. It reeks of someone who has no idea what the "0/5W" designation actually means. In this modern age of high performance synthetic oils, there is zero reason to use 5W-anything when the 0W-equivalent exists. You want the oil to be as thin at room temperature as possible so it actually gets to your bearings as fast as possible on cold starts, and 0W oils excel at this far better than any 5W could ever dream to. The "30" is the important part here, as it means the oil will be equivalent to a 30 weight oil when warm. Personally if I was tracking this car I'd do 0W40 instead, but I'm just some rando on the internet who claims to know a lot about cars so do your own research.

To make these engines last, the name of the game is avoiding damage from sustained high load/low RPM condition. Full boost at/below 2000 RPM is not only right in the LSPI zone, it's also terrible for your rod bearings since you're at a lower oil pressure and have reduced oil keep-metal-surfaces-away-from-each-other ability as a result. I see recommendations to not accelerate in 5th and 6th gear but personally, once the car's revving over ~2500 RPM (or more accurately, once oil pressure is over 50 PSI) I treat 5th & 6th no differently than any other gear and will happily go WOT to pass someone without bothering to downshift; the risk of damage simply isn't there at higher engine speeds and oil pressures.

TL;DR: If you've blown up your GR Corolla it's probably due to a skill issue. Fight me 😈

 

To make these engines last, the name of the game is avoiding damage from sustained high load/low RPM condition. Full boost at/below 2000 RPM is not only right in the LSPI zone, it's also terrible for your rod bearings since you're at a lower oil pressure and have reduced oil keep-metal-surfaces-away-from-each-other ability as a result. I see recommendations to not accelerate in 5th and 6th gear but personally, once the car's revving over ~2500 RPM (or more accurately, once oil pressure is over 50 PSI) I treat 5th & 6th no differently than any other gear and will happily go WOT to pass someone without bothering to downshift; the risk of damage simply isn't there at higher engine speeds and oil pressures.

This right here.

 

I'm not watching the video, but my opinion is this guy ^ was tuning his own car. He just recently has been asking about changing the valves in his engine to improve engine reliability, all while having a full warranty on his BRAND NEW GRC. He killed his own car not toyota.

Edit: Burnt car guys recent Facebook comments lead me to believe he blew up his engine by doing a 130mph pull before it got to operating temperature.

 

View attachment 30391
I'm not watching the video, but my opinion is this guy ^ was tuning his own car. He just recently has been asking about changing the valves in his engine to improve engine reliability, all while having a full warranty on his BRAND NEW GRC. He killed his own car not toyota.

There's always more to the story.

 

Modern street engines have low tension piston rings by design.

 

Just an opinion; mine is a bone stock Morizo, and I never let the rpm’s drop much below 2300-2500 in any gear. It doesn’t feel ‘happy’ below that rpm band especially in 4/5/6th. In the old days we’d call that feeling of being below the proper rpm ‘lugging’ and that’s the sensation I get with it in the upper gears below 2500ish, so I keep it above 2500 and it feels good (above 3000 and it feels like a REALLY happy motor!)

FYI my FK8 will happily run along at 1800-2000 in the upper gears without that lugging feeling at all.

 

Regarding oil weights, I don't know anything about LSPI protection being different for different viscosities, but it makes sense in his scenario. Going up in viscosity is a proven way to improve the physical protection of the engine. You trade it for some marginal loss in efficiency and marginally higher temperatures from pumping a slightly thicker fluid. It's described well in some of Lake Speed's videos talking about wear and friction being mutually exclusive, and typically at odds with each other. The thicker viscosities however handle heat much better. A 0w20 is great for daily driving and maintains its intended viscosity and pumps easily when really cold, but gets scary thin at high temps like what you'd see at the track. The idea is that a 5w30 at 240°F could maintain a similar film thickness and protection that a 0w20 can at 210°F. I don't know what those actual temperature thresholds are but you get the idea.

 

Increasing oil viscosity also increases the risk of LSPI. Especially when the engine isn't fully warmed up. For a street driven car with stock engine, I see no advantage of deviating from manufacturer specified viscosity.

https://bobistheoilguy.com/forums/threads/how-oil-affects-lspi.289995/

 

Just had the video pop up on my YouTube feed. He blames the issue on ring gap but refused to measure or tell us the stock ring gap numbers. That would be a critical measurement for us to know.

 

In his video ( not mine) he mentions it to be a common problem on First Gen GR Yaris. I see that they started production in September 2020. I have no info on what common parts we share with that engine. I’m wondering about his recommendation to change to 5w30 and if that does affect blowby. Thanks for the info and discussion.

 

Thicker oil historically can reduce blowby somewhat by simply being thicker, further preventing combustion gasses from pushing past the rings. Its also a little less volatile so the PCV/CCV system has less vapor to collect and route to the intake. LSPI goes the other way, it can be caused by the oil itself getting into combustion chamber. To some degree (I'm not sure how much) thicker oil can apparently increase LSPI likelihood by being a little more tenacious; a thicker film will resist scrape by the piston ring and allow marginally more oil into the combustion chamber. But again LSPI events require conditions with a combination of high boost under high load at low rpm.

So use a good API SP GF6-A oil (these indicate LSPI ratings), and good driving habits (don't lug the engine at low rpm) and this is not a concern. If you generally just put around town, stick with 0w20. If your engine gets run hard, consider 5w30. If LSPI events were caused by just using 5w30, or lugging the engine occasionally, we'd see failures left and right. Instead we're seeing a very small number of cases get "blown" (har har see what I did there) out of proportion and spreading FUD.

 

The grc tht caught on fire was tuned?

The grc tht caught on fire was tuned?

From the thread you quoted with emphasis added - "....my OPINION is this guy was tuning his own car."

 

Well apparent in the Facebook messenger group there is a guy here in LA that did have his engine blow up at 16k when he was shifting gear at like 5 k going to 2nd just driving around town about 2.5 months ago. This is the first I heard he literally just mentioned in on the messenger app.

 

Well apparent in the Facebook messenger group there is a guy here in LA that did have his engine blow up at 16k when he was shifting gear at like 5 just driving around town about 2.5 months ago. This is the first I heard he literally just mentioned in on the messenger app.

I'm sure in the next year or so we will see a few more once there are more cars in the road. I just have a grudge against that one instance.