GR Yaris Are these engines really this fragile?

[6mt]

I find it hard to believe that all GRY/GRC engines have this issue and could fail catastrophically at any moment, even in stock form, while using the highest grade oil and fuel.

Thoughts?

 

[6mt]

Interestingly, someone else already checked Toyota's Microcat for the original piston part numbers for the GR Yaris (Gen 1 and Gen 2) and the GR Corolla. Here’s what they found:

- GR Yaris Gen 1: 13101-18030
- GR Yaris Gen 2: 13101-18040
- GR Corolla (up until September 2024): 13101-18040
- GR Corolla (from September 2024 onwards): 13101-18050

Notably, the latest GR Corolla has different pistons compared to the GR Yaris Gen 2. This raises the question: Did Toyota actually fix the problem in the GR Yaris Gen 2?

Despite these different piston part numbers, all of them use the same piston rings: 13011-18040.

 

[Onehp]

I've worked in warranty. A high stressed engine, real worlds conditions, many parts involved there is always a certain failure rate. Only Toyota will sit on the correct data. Ten engines mentioned in the second vid is quite anecdotal without context, and I kinda doubt many of them were 100% stock. Car manufacturers will dyno and test the hell out of their engines before releasing them, but a badly judged tune or box is all that is needed to throw all that works out of the window....

This is already being discussed here also

GR Yaris - Balance of tuning and durability limits

I’m still yet to see a destroyed GR Yaris engine running on stock form. He says there are, with no more data but it is difficult to trust his claims. There may be a few, nothing odd when there are ~30'000 of them around and that's what warranty is for. Also the reason I created this thread, it...

www.gr-zoo.com

 

[Michael Knight]

Interestingly, someone else already checked Toyota's Microcat for the original piston part numbers for the GR Yaris (Gen 1 and Gen 2) and the GR Corolla. Here’s what they found:

- GR Yaris Gen 1: 13101-18030
- GR Yaris Gen 2: 13101-18040
- GR Corolla (up until September 2024): 13101-18040
- GR Corolla (from September 2024 onwards): 13101-18050

Notably, the latest GR Corolla has different pistons compared to the GR Yaris Gen 2. This raises the question: Did Toyota actually fix the problem in the GR Yaris Gen 2?

Despite these different piston part numbers, all of them use the same piston rings: 13011-18040.

assuming the rings installed will not be adjusted by gap during install (?) but are in spec from the factory so it would return the same issue in all engines (if such issue exist, in first place). if it would, one might think Toyota would react.

 

[6mt]

I've worked in warranty. A high stressed engine, real worlds conditions, many parts involved there is always a certain failure rate. Only Toyota will sit on the correct data. Ten engines mentioned in the second vid is quite anecdotal without context, and I kinda doubt many of them were 100% stock. Car manufacturers will dyno and test the hell out of their engines before releasing them, but a badly judged tune or box is all that is needed to throw all that works out of the window....

This is already being discussed here also

GR Yaris - Balance of tuning and durability limits

I’m still yet to see a destroyed GR Yaris engine running on stock form. He says there are, with no more data but it is difficult to trust his claims. There may be a few, nothing odd when there are ~30'000 of them around and that's what warranty is for. Also the reason I created this thread, it...

www.gr-zoo.com

Thanks for pointing this out. I didn’t realize it was already being discussed in another thread.

 

[markku]

I find it hard to believe that all GRY/GRC engines have this issue and could fail catastrophically at any moment, even in stock form, while using the highest grade oil and fuel.

Thoughts?

This youtube channel leaves me always full of doubts...
It's usually much competent and thorough, but sometimes it looks like it exaggerates things too much.
Once the Mk2 was launched, their first video was like "About time, the Mk1 has so many problems that a new model was long overdue", and this was after many of their videos celebrating the qualities of Mk1.
Then this video.
For sure it's useful to know about it, but the problem they highlight is described really as a random one, that could happen on any Mk1 car, if bad circumstances align in the wrong way in a sudden deceleration.
And in the end, he contradicts himself by telling us not to worry, because it is a problem limited to few cars...
Not true, because if the cause is related to a design flaw in all pistons, then it could really happen on any car with stock pistons.
I guess this should not be classified as a severe design flaw, but as a random problem that could occur to any engine with high performances, otherwise all 40k Mk1s in the world should get a broken engine sooner or later.

 

[Michael Knight]

This youtube channel leaves me always full of doubts...
It's usually much competent and thorough, but sometimes it looks like it exaggerates things too much.
Once the Mk2 was launched, their first video was like "About time, the Mk1 has so many problems that a new model was long overdue", and this was after many of their videos celebrating the qualities of Mk1.
Then this video.
For sure it's useful to know about it, but the problem they highlight is described really as a random one, that could happen on any Mk1 car, if bad circumstances align in the wrong way in a sudden deceleration.
And in the end, he contradicts himself by telling us not to worry, because it is a problem limited to few cars...
Not true, because if the cause is related to a design flaw in all pistons, then it could really happen on any car with stock pistons.
I guess this should not be classified as a severe design flaw, but as a random problem that could occur to any engine with high performances, otherwise all 40k Mk1s in the world should get a broken engine sooner or later.

In my opinion GR has been designed to meet a certain performance. its good for its purpose, but if you plan to get 350hp from it with a chip tune then good luck with the engine longeivity. Suspecting all or most of the failed engines have had quite serious abuse and/or tuned engine. The oil system in the car is not perfect especially if tracking, but dare to say it will not explode if you drive normally and service it normally. So yes, the topic is bit a tempest in a tea cup.

 

[cuddles]

I suspect these 10 engines have been modified and driven in a way that the vast majority of us won't replicate.
It got me trying to remember other makes of car that have had serious engine problems.
The first I came up with was the ford engine - I believe on their RS ralley version and other eco engines.
Recently seen a report about Stelantis engines causing problems again with wet belts.
I am sure other people can remember other engines so a few toyota engines going bang is par for the course. It seemes to be lifting off at high speed sudenly.
I doubt it is a problem for the vast majority for us but does remind me how important my yearly service down at my local MrT centre is - and driving it respectfully to my little 3 pot.

 

[markku]

In my opinion GR has been designed to meet a certain performance. its good for its purpose, but if you plan to get 350hp from it with a chip tune then good luck with the engine longeivity. Suspecting all or most of the failed engines have had quite serious abuse and/or tuned engine. The oil system in the car is not perfect especially if tracking, but dare to say it will not explode if you drive normally and service it normally. So yes, the topic is bit a tempest in a tea cup.

Exactly, I totally agree with you, and what's really a too long shot in this video is stating that it can happen to any engine, any car, at any time, even to 100% stock cars that never saw a track.

 

[markku]

I suspect these 10 engines have been modified and driven in a way that the vast majority of us won't replicate.
It got me trying to remember other makes of car that have had serious engine problems.
The first I came up with was the ford engine - I believe on their RS ralley version and other eco engines.
Recently seen a report about Stelantis engines causing problems again with wet belts.
I am sure other people can remember other engines so a few toyota engines going bang is par for the course. It seemes to be lifting off at high speed sudenly.
I doubt it is a problem for the vast majority for us but does remind me how important my yearly service down at my local MrT centre is - and driving it respectfully to my little 3 pot.

Sure, I remember that Ford mounted a wrong gasket (from the Mustang, if I remember well) on some engines of the Focus RS Mk3, causing bad lubrication, and engine failures in the worst cases.
That was really a bad mistake by Ford, and I'd say that nowadays engine failures are mostly caused by bad (and evident) production mistakes like that or by extreme self-mods.

 

[6mt]

Yeah, the first thing that comes to mind are the infamous rod bearing failures in the S54 and S65 engines. The irony is that 99% of owners who religiously warmed up their cars and performed regular oil changes never faced these failures, despite how common they were made to seem, with the internet blowing things way out of proportion.

What I’d really like to know is how many bone stock GR Yaris models have actually experienced this failure, with a verifiable source to back it up. So far, all I’ve heard is hearsay and ‘trust me, bruh’ kind of evidence.

 

[Chris_P_Bacon]

Yeah, the first thing that comes to mind are the infamous rod bearing failures in the S54 and S65 engines. The irony is that 99% of owners who religiously warmed up their cars and performed regular oil changes never faced these failures, despite how common they were made to seem, with the internet blowing things way out of proportion.

What I’d really like to know is how many bone stock GR Yaris models have actually experienced this failure, with a verifiable source to back it up. So far, all I’ve heard is hearsay and ‘trust me, bruh’ kind of evidence.

Yup i agree! That video is on 14K views and over 300 comments now. Surely some of the "30 in Italy only "engines that have allegedly gone bang are in or read this forum. Lets start making a list of blown engines because this guy AJ or Toyota are not going to confirm either way. I only deal in facts and data like most of us.

I find his video very frustrating to watch with his secrets and "trust me" attitude, but at the same time watching and reading the comments I can see some reasoning there.

I'm just going to sit on the fence for a bit and see what happens. This video is certainly not helping the reputation or stigma of the car for sure..........

 

[Chris_P_Bacon]

These are my rambling thoughts on this subject.......

We all know when he's talking about his colleagues and friends he's talking about ACME but he wont say. Now if your an ACME or a Lamspeed, Litchfield, Whiffbitz etc etc your gonna see broken engines because if it does go bang your probably going to go see these guys for a rebuild, funds permitting. So if ACME have seen 10 or 15 engines in the last 3 years? I get it. But he is also throwing around figures of 30 in Italy ( without evidence).

I know of a few, not personally that have died in the UK, but as usual no further info on why. I've seen one or two disappear off the face of the earth after being seriously upgraded by notable tuners or whilst being there for the owner to "not have the car anymore" or " i cant say".......... but this is understandable also. I've also seen a couple of public rants were Toyota have knocked back warranty work to replace an engine, but again this could be understandable too, missed services, tuned, etc etc.

The oil! I get the 5W30 he's proposing but i think the 30 is possibly more important than the 5? I'm guessing bearing and engine clearances that were built for 0W20 possibly wont like cold temps and a thicker winter weight, but i'm also informed that some Toyota dealers across the world have adopted this? Possibly warmer climates maybe? The camshafts are hollow and the lobes are a pressed interference fit with a few failures here and there with lobes moving and pump gears being ripped off the end in extreme cases, i mention this with regard to changing oil spec to a higher weight and would this be worse for this phenomenon?

Wrong oil, sure we all know the reason the GF6 is needed, could the wrong oils, SN etc produce knock? Deffo if it gets in the wrong place. This leads me on to the rings as he mentions, this "slacker ring" tolerance i think is a current Toyota trend across a few engines and i think it has something to do with emissions and materials used in the bore etc for compatibility and expansion. Could it be a problem? surely if the rings were not keeping the oil in the right place we would see some seriously smokey cars, but I don't know enough on that subject. I do know that direct injection petrol engines benefit from regular oil changes as the chance for fuel to mix with the oil is higher so that makes senses also to combat knock. The jury is out on the oil weight change for me.

Could the trend for the slight overfill of oil to combat oil starvation on track be detrimental to oil ending up in the combustion chamber? Too much pressure? what a can of worms eh.......

He's basically saying the oil is getting past the rings, mixing with fuel, mega detonating and shattering the piston. From the scarce images i've seen of these engines once broken, I see a lot of shattered pistons, normally just one and almost always an intact rod that has made its way out of the case so I cant disagree with his point about the piston shattering on a basic level. I think if all the clearances of the rings were wrong like he says there would be more evidence across multiple cylinders not just one. Could there be a bad batch of pistons? Sure why not? The Gen 2 has a new piston doesn't it.

Could poor tunes that haven't got enough headroom left to pull timing once knock is sensed be problem? I'm sure a batch of poor or low octane fuel and a badly mapped car is what nightmares are made of.


In summary I haven't got a clue, but I think its worth discussing.

 

[Michael Knight]

I know two engine issues - first one likely due to oil starvation as car saw lots of track time and the oil level was not in max but lower.
Second one was the piston 2 explosion and current analysis is that it was because of poor fuel, (race) car was running motec and the analysed octance rating was 97.2 that is too low maybe for the map used.
So in both these cases the reason was likely something different than the piston rings or pistons.

 

[tonic]

Second one was the piston 2 explosion and current analysis is that it was because of poor fuel, (race) car was running motec and the analysed octance rating was 97.2 that is too low maybe for the map used.

Or it could be bad tune?

 

[Michael Knight]

Or it could be bad tune?

define bad tune. if the map has been designed for race fuel and for oct98, it doesn't work with lower octane.

 

[tonic]

define bad tune. if the map has been designed for race fuel and for oct98, it doesn't work with lower octane.

I’m not sure I can give you a dictionary-worthy definition of a 'bad tune' but it could involve things like poor fuel and ignition mapping, incorrect transient handling, temperature mismanagement, and so on. I'm not an expert, though. Bad – the kind that blows an engine, I guess.

In any case, hard to blame the engine if it was running different ECU and custom mapping.

 

[Michael Knight]

I’m not sure I can give you a dictionary-worthy definition of a 'bad tune' but it could involve things like poor fuel and ignition mapping, incorrect transient handling, temperature mismanagement, and so on. I'm not an expert, though. Bad – the kind that blows an engine, I guess.

In any case, hard to blame the engine if it was running different ECU and custom mapping.

if you use the car with the fuel that it is not intended to, its not a bad tune, its a poor maintenance and use of the vehicle.
unfortunately in this case the fuel was not in the spec what it supposed to, so safer use higher quality racing fuels.

 

[GRandemakina]

A word about "bad fuel":
1st: personally (and so far) on my own car has never seen other than 98 - even if, when I picked up the car from Toyota dealership the seller offer to brim the tank full of 95 - declined!!!
2nd: being in Europe, the car shall handle 95 oct fuel without blowing up or reduced longevity - and that's a legal requirement!
The only acceptable side-effect could be some performance detrim.. (eg. ECU pull back timing, boost,..)
From factory the car SHALL have means to deal with "bad fuel" - once again, without shredding to pieces if you shout "95" aloud!
3rd: as most of us here - GRY nerds - I know that this particular engine have details/tech that highly relies on good fuel (being over-stressed for it's capacity, with high boost and hi compression ratio, direct injection,...) therefore, for me I try to play safe in terms of fuel quality, oil quality/dilution, crank-case vapors and heat management - especially considering, that I suspect Toyota may have overlooked some worst case-scenarios, or combination of...
4th: Mapped/tuned: another, completely different can-of-worms...

 

[GRWTF]

Start stockpiling the parts for when your clutch goes and do it all then. Not a big deal. The sky isn't falling.