Given this is a homologation model, I would have thought spare engines would have been available for racing teams? Maybe you have to order the spare engine when you buy it.
Fascinating to see the insides of the engine on such a new car, and great to have a dealer that lets you get in and see the work in progress like that. Love these technical videos, please keep them coming.
@@RobertMitchell I rebuilded my old Celica gt4 for Weeks at their garage. They are very helpful and Michael is a great Chief. Bekim and Waldemar are my tier 1 mecanics!
What car makers won't tell you that power output relative to engine capacity in modern turbocharged engines is such as it was it group IV (highest competition class) cars in the early 80s, while materials remained the same. In most cases, no magnesium, no titanium, no ceramic alloys, just iron, steel and aluminium. Back then these engines were supposed to do 3-5 thousand kilometers before a complete rebuilt. These modern engines are effectively competition engines and owners should have over-average technical knowledge if he doesn't want to damage then in no time.
As a mechanic, I absolutely LOVE how apparent it is that Robert has wrenched and built engines himself. Also, how awesome of the Toyota dealer to let you film this in there!
You're a nice and honest guy Robert. Without saying anything, with no warning from the computer, the cost would have been fully taken on warranty, come on Toyota, give Robert a discount ! Loyalty pays, this would be a great example.
I agree but usually by using cars on track you loose warranty anyway, but yes it would be nice if they would share the costs, the rocker arm shouldn´t have failed at such a small overrev, i think this was a material issue anyway. I did the same with an BMW 430i at the german Autobahn, wanted to shift to 4th at around 130kph and accidently choosed the 2nd but luckily nothing happened my first ever missshift :D intersting how many lights can flash at the same time in a modern car cockpit and the engine turned off immediately automatically :D:D but tbh it was the only way i ever found to switch off the ESP System. Because i was still roling and restarted the engine there was an ESP-failure which took it off :D:D but I wouldn´t recommend this.
@@KirkVSSpock 😅 just waited for this answer, this could be a nice meeting at the court. Customer: it is a legal road not a track! Tyota: okay so, why you are going 200+ on legal Road where 100 is allowed, maybe we should talk about your mental ability to drive a car on public roads. Customer: okay, how much is the engine:D
In a way you've effectively done an accelerated stress testing on the engine and highlighted the component most likely to fail (the bearings for the valve rocker arms) Something for Toyota to pick up and work on in their next iteration.
I think it's the other way round - I think the big rev difference stretched the chain, caused the timing to go out so the piston hit the valve, and that's what caused the other damage... pushed the valve up while cam follower was trying to push it down, and then it was just a matter of time until the follower failed and caused the valve to drop which was when it got bent
It's a thought but you cannot normally extrapolate from an abnormal situations. There was a famous airbus crash after the pilot gave too much rudder inputs which took it beyond the design limitations and ripped off the tail. Pretty sure they didn't try to strengthen the design after that.
@@jamescaley9942 I agree they might not do anything about it, especially if it was a user error, but continuous improvement is the Toyota Way after all. So who knows...
@@Richard_AKL If the timing chain had stretched then the whole cam would be off and other valves would have hit pistons too. Roberts explanation is much more likely given just one intake valve was affected.
I'm far from being an expert, but if the ICU doesn't show over-rev, it would indicate that the engine remained within manufacturer spec, and the actual cause of the breakdown was a manufacturing defect inside one of the bearings, which might have been revealed through a slight over-rev, but then again, it might have just failed after a heat-cycle. In any case, I think Toyota should think about covering the expenses.
Agreed! If it was still within spec enough that the ECU didn't log it, it sounds like the overrev was minimal and possibly still within red line. Of course, I'm not sure Robert cares so much about the cost of the repair on a Yaris compared to a lot of the other cars in the fleet, the downtime is a lot more costly than the repair. I appreciate Robert's honesty but this is definitely a situation where a causal omission would have gone a long way. That said... Misery means clicks, so he probably will earn more money admitting it than not!
It's an interesting problem. Whether there is enough data logged to get a meaningful sequence of events out of it, whether the parts can be X-rayed or microscoped to expose a potential weakness etc. Maybe get Toyota interested and ship the damaged parts to Japan? In retrospect, as long as there is no overrev logged, it *would* have been a warranty job.
I think the cause might be not even the over-rev per se but the over acceleration of the affected parts. Just to put in some numbers going from 2000 rpm to 7000 rpm in 5 milliseconds might be ok for the bearings and lubrication... and springs... but going from 2000 rpm to 7000 rpm in 0,5 milliseconds might cause damage like ejecting a retainer pin although the engine isn't really overreved.
@@kreiseltower na, accelerations isn't an issue for the rockers. At 7000 RPM, the cams are rotating almost 60 times per second. So the rockers are going up and down every 20ms. Acceleration of the engine wouldainly hurt the transmission, and maybe the timing chains, but not throw a rocker off.
@@kain0m I do not mean acceleration of the car, but angular acceleration of that bearing where the rockers sit on etc... I don't remember exactly, but how does that axle of the rocker mount sit on that bearing? Is it a press fit? There must be a (design) limit on how fast you can accelerate or decellarate from one rev. number to another and this could have been the failing point.
Robert, you must be very proud to be the first in the world to grenade what is already becoming an icon auto. Congratulations! (PS; said with love and irony)
‘Ultimately’ one of the more cool videos you guys have made - thank you, really learned a few things from this whole story. Narrowly missed a “money shift” myself on my gt3, boy am I glad!
@@RobertMitchell I was incredibly lucky, I shifted to 2nd and began to release the clutch when I saw "2" on the dash in front of me and 'clocked' that wasn't what I wanted to do, I had hardly released the clutch by a few millimeters. The 991.2 shift is incredibly close across the gate.
@@RennieAsh perhaps it was the 'resistance' that I felt that made me aware of the mistake I was about to make, but I'm pretty sure it would have made the shift. Certainly, there are others who have made a similar mistake (with disastrous consequences). I find the manual box in the GT3 to be a bit too easy to shift (little resistance as compared to say my old 997), couple this with the short throw and very closely stacked ratios, and it's almost a recipe for disaster (certainly for hacks like me).
For those of us who have a interest in this engine and it's engineering, we find this video very educational and give us a small idea of what to keep a eye out for,when it comes to high Rev. The fact that you showed us the physical part's while explaining the damage results and your plan for the rebuild got my attention being that this engine is becoming more popular in the automotive and car world. So thank you.
Wow, I can't believe that tiny little engine has that much power. I would expect that engine to be in a 1968 Volkswagen Beetle but not in a 2021 GR Yaris. It's a technological marvel.
superb video .. lucky owner .. at 76 years old I tend to baby / granny my motors . I believe my Perodua Kelisa car has the Toyota Yaris three cylinder motor . It is so nice to see how well built the engine is .. That piston is perfectly usable .The chance of a failure goes up exponentially with RPM. and of course mileage .I ran three engines when I won the 1980 Donnington GT championship. the practice and race engine had the cylinder head removed the camshaft buckets were inspected and the valves re seated with 1mm wide rounded seat faces . Apart form a broken crankshaft at Oulton Park racetrack . I never had an actual engine failure .9,000 rpm max self imposed rev limit .on a much modified 1 litre Hillman imp engine .
Admire Robert for the honesty and taking responsibility for the damage. Time will tell if the over-rev was actually severe enough to cause the problem, or if we will see similar failures in other GR Yaris in the future. I do find it a bit interesting that only the one rocker arm bearing was damaged from the over-rev.
I've seen every video on the blown engine Yaris GR, and specially on this video, I can tell that you are really passionate about Cars. It's not only for your technical knowledge, it's also for your driving style to take care of the cars, the technical and not technical chats, and of course, for a little thing called apex. Hoping that if in a near future I travel to Germany, could stay in Apex and have that nice experience of the Nürburgring with people who just love cars. Greetings from Argentina!
Possibly soon the most watched automotive video? It's the unicorn of unicorns! Finding content about broken McLarens, Ferrari's and Mambo's is no problem at allj
Toyota engineering is pretty incredible at making their stuff compact, buildable, maintainable, and generally bulletproof. Lots of other makes tend to get only 3 out of 4 of those right (some less lol). That engine is a work of art.
Robert, very impressive Tech Talk. I enjoy the in depth sharings when dealing with fixing and improving the fleet. Thanks! Glad that the catastrophic failure was not a total catastrophe. Looking forward to the next part of the rebuild and a return to the Apex fleet for laps.
Lets see, if this problem apears in some other Yarises over time, then it maybe some manufacturing fault. Light overrev should not cause that rocker arm bearing center pin come off loose.
It depends of the engine. I remember my bestie, that wa driving the shit out her Mazda MPS. She also had engine failure, but was driving like a maniac, missing shifts all the time. When the engine gave up, she claimed a malfunction of said engine. But I guarantee you, she would have broken ANY car in driving like that.
Robert first off, kudos for looking at the silver lining even through a bad experience. Second, I appreciate your taking the time to explain all of this to noobs like me. Much appreciated!
The theory of Robert sound quite interesting to me, however there is another conclusion would could have happened to the engine. By overreving the engine, the Valve spring failed to get the valve back up in time, therefor the listing hitting the valve, breaking the retainer clip and then breaking the other parts of the engine control. Anyway, really nice Video and interesting to see. Also Robert does a great Job of describing the engine parts and how they work. Keep up the good work.
I wrench at the third dealership of my career. I've never had a problem if a customer wishes to see their car when it's torn apart. I had a customer take pictures of their engine and then post those pictures on an enthusiast forum. That might be the extreme though (that was about 12 years ago), but I think if the customer just wants to look and ask questions of the technician they would first make sure the tech is OK with it first and then let him come in, especially if the customer is paying for the repair vs warranty.
Great breakdown on the failure Robert! You really dodged a bullet if all of the debris stayed in the top end of the motor. It wouldn't take much for one of those needle bearings to make its way into the bottom end and cause some major carnage. Good call on replacing all the rockers, they all endured the same overrev and I wouldn't want another one to decide to let go shortly after the rebuild. Any thought of trying to source some forged internals and upgraded valvetrain "while you're in there"? Keep up the excellent content!
Man. Watching stuff like this brings back some pretty good memories of automotive shop class in grade 9-12 for me. I live/went to school near a General Motors office, so our shop was all old GM V6s and similar, plus a Chevy cobalt that I think was like an original late-stage prototype (looked like any other cobalt, but I think it came from the engineering dept.) test car that got donated to the school. Our teacher wasn’t super well organized, so most days in grades 9-10, we were just told to go take something apart and put it back together again. One “big project” we did through a semester was taking apart and reassembling one of the old engines. Good times. (And looking at it now, I write that like it was ages ago, but it wasn’t _that_ long ago).
I posted this in another video without response. This is a known issue with the V6 engine the 3 cylinder is based on when pushed to higher sustained RPM. Check out some of the information from the SW20 MR2 guys who swap the Camry v6 in to that chassis.
@@NoClassic So you're saying that the G16E-GTS i3 from the yaris could be a 3GR-FSE v6 cut in half with a slightly longer stroke? Bore and compression ratio is the same and it's also open deck, but the yaris has direct and "indirect" injection which i guess means port injected.
@@peejayem4700 Yet is still uses the same rocker design as a number of other engines within the Toyota line. Toyota is successful for many reasons , one of them being recycling of components and in turn engineering time among powertrains.
Thankyou for the explanation, the last video was quite forensic and seeing the parts adds to the understanding. I really appreciate you taking the time to do this!
Quick question - that you could see the marks on the top of the piston compared to the main surface looked like something had worn off - was this a coating or simply carbon/soot from normal engine running?
Thank you for sharing the progress of your GR Yaris motor. Your failure analysis skills are pretty good! If the ECU log doesn't show an over rev, I'm wondering if there was a manufacturing (assembly?) defect from the factory.
Thank you for taking time to make an informative video out of this misshapening Robert. It was pretty cool to see that little beast engine with so much detail
I wrote this comment with hate in my heart because I work in finance and am studying engineering, and just lost my cool about this very successful person having what I thought was poor attention to detail. What he actually has is the resources to have other people take care of this stuff and is also sharing the journey with us - both of which I both appreciate and respect. I've deleted what I originally wrote because it adds nothing to anybody's life, least of all mine.
At what point do you think that the locks came out? You’ve sure come in here with an attitude didnt you?! 1. When do you think the locks came out 2. when do you think the valve hit the piston?
@@RobertMitchell Either the spring surged massively and let the locks out OR the piston hit the floating valve, jamming it in the guide, which would cause the rocker to slide off the stem, onto the retainer, letting the locks out. It doesn't make sense for an over-rev to cause a needle roller bearing to fail before anything else. It's the one part with no reciprocating energy.
@@RobertMitchell I can't believe that the rocker failed first, so it had to be the locks coming out or valve-on-piston violence that kicked it all off. Both would require some mighty spring surge, but are possible.
SIx or seven years ago a friend and I rented a 325i from a local provider, and alas my mate found 2nd whilst looking for 4th on his second lap of the day. The shape of that valve is very familiar - that following December, my mate received a Christmas card here in Australia from the car owner, with two very similar looking valves enclosed, cleaned and polished! An expensive souvenir but he can laugh about it now.
He said like 13k rpm.... So, I'm guessing revved to like 9k and damaged but not destroyed? Think they ecu would record 2k over redline, and figured you need at least 2k over to damage and dismantle parts like here
That is catastrophic for any other engine. I’m impressed that there isn’t more damage. I’d be worried pushing these to its limits until there is a better rocker/bearing upgrade.
How much did you ask Toyota to pay you for the honor of fixing your car? 🤣🤣🤣 Great in depth look at this pocket-beast of an engine. Hoping to see it back in action soon
@@fabini14A closed deck design is MUCH stronger and even better using cast iron vs aluminium. This design the Yaris uses (OPEN DECK block & aluminium cast) is purely for cost cutting, or in marketing speak "weigh reduction". But its a much weaker engine design and prone to cracking especially on high compression turbo charged engines . Also limits any further modding of pistons or over boaring the block also. Overall not the strongest engine.
If no over-rev is logged then I would have thought this would be covered under warranty? I hope this is a failure point that is corrected in later cars. Mine arrives May '22.
Can they really read the ECU rpm data back, for 5 laps which is 100+ km? Might have been the good old "Kid, I saw you smokin'..." trick (even though you didn't, obv.)😁🤷♂️.
@@jamescaley9942 Some premium ECUs hold timers which count how long have you been above certain revs. It would look like a given rpm and time the motor was above that. it takes one timer and a reference value and it does not use a lot of ECU memory.
@@jamescaley9942 I would expect it to hold some data for this to protect Toyota from warranty claims that are due to buzzing the engine and not being open like Robert has been.
In my opinion as a former employee as a engine rebuilder in a shipyard this bearing did not fail in the over rev situation. If it should fail during the over rev it would be because the valvespring couldn't keep up the pace of the engine and the Inlet valve didn't close in time resulting in contact with the piston. Then the valve hits the rocker with too much force and the bearing fails. The engine would fail at the same time as the over rev because the valve would bend at the same time. Not the next day after sending the car 5 more laps. I think warranty is a possibility. BTW why did they take the engine out? I can't imagine that they would take it out for a headgasket we're basically the same parts come of the engine. Thanks for the video Robert. I was waiting for it👌
@ rexsolomon : Well if you order it now, you might be lucky to still be able to get one. Most countries' allocation are sold out. If you are lucky to be able to order one, delivery not before Jan 2022. This car is already a collector while being brand new !
It really is great, from three, four or five points of view. You look like you are really enjoying working with thd dealer and their mechanics there. And, as you say, building a relationship! There has been super transparency - for everyone in the GR community - and us too, along for the ride. It feels so quick. And now great to take a rest. The GR, too, warm and happy inside.
Agreed. Recently helped check a 944turbo engine.. debris had hit the piston and the top ring was almost siezed in the grove as the piston had compressed a tiny amount.
All in all not so bad in the end. Good to look at a positive angle like that. If no over rev was logged have they still said mis shift or mechanical failure?
As always, thank you for high-quality no BS content. Those cam shafts and timing (VVT?) badgers are so beautifully made and finished. makes that car so such good value for money! (in relative terms).
So very cool! We all guessed the engine was a gem but seeing the whole engine bay stripped out and the parts, it's genuinely impressive engineering. Good call on replacing stuff too, not worth the risk to reuse already stressed parts
Looks like a Japanese motorcycle engine. I think it's interesting that we are seeing 3 cylinder engines in the Yaris, Mini Coopers and BMW I8. I guess it is a cost saving over 4 cylinder?
EU Emissions standards. They're taxing ICE sales over 99g/km now and giving that money via carbon credits to Elon Musk. Ignoring the fact that something like an VW ID.3 is 119g/km before you even put any electricity in it!
@@sang3Eta Well said man, even though I'm not sure about the Elon Musk part. However, you're absolutely absolutely right about the CO2 tax. In France to buy a Yaris GR-4, it's 6039 € CO2 tax (in 2021 - 7600 € in 2022) to add to the price tag. Won't see many GR-4's registered in France for sure. Many people that buy EV are not aware that the equivalent CO2 "weight" the construction of an EV and it's battery has before even starting to drive... They are so sure in helping the save the planet from us bad petrol head polluters...
Nice to see you are not taking any risks when it comes to replacing parts that are even slightly damaged which is the smart move when you are going to be thrashing it round the ring.
God you’re such a good teacher ! That tops up on the fact that you’re always so humble. Such a good person you are !! I’m happy that I’m following Misha to discover you and to follow you as well now!
Not sure about Toyota but the PCM in a Ford Mustang GT350 told us the engine had revved in excess of 9,000 RPM. That car had been "money shifted" at a track and threw 2 connecting rods into the plastic oil pan and melted them into it. Also crushed the rod bearings and just massive mechanical carnage in that engine. It was pretty cool to see.
I would love to see Robert Mitchell and Sandy Munro talk about car engines. Both guys are humble, brilliant, but they come at the topic from different angles. It could be very interesting.
Great upload as usual.... You know one of the great things about your channel Robert and company.. it's CLARITY ... From the cameras clarity , to the no nonsense attitude of your character, to the stance you take on certain bullshit and the the honesty.. it's clarity throughout it all. Reminds me of times before the internet ruined us all😂 .. there's your new tagline... Clarity... Btw picked my GR up today and only driven 5 miles... When it's run in and borders open I'm coming to Apex . Cheers Robert 🍻
@@RobertMitchell at least you are open about it so they should do the warranty under the good well stand point of giving some discount / free parts ...although not much. It would be a happy ending somehow!
Dunno if you got lucky, or if it's just a good design by Toyota, but that does look like really minimal damage and I agree that it makes sense to replace all the rockers. If those are the engineered failure point, the others could well be on the way out. You gonna keep that piston? :D
