V6 piston failure

[Julian73]

On 5/8/2017 at 13:19, NedaSay said:

Except that 87 is way worse than 91...  In order to cope with our bad fuel, Lotus and other manufacturers do have to remap the ECU so that the engine keeps delivering performance,  If some do wonder why the Sport 410 does not deliver the same torque figures over here look no further than that.  

Now considering that the 2-GR is built to be bulletproof, a bad mix of bad oil and bad fuel could still kill the car's engine. It would take a lot though, especially considering that Toyota QA process is "very thorough" and Lotus doesn't touch the block, it can still happen. Although if 10 cars in Italy have been subject to that while we haven't heard of such troubles anywhere else I think is extremely weird.  Now the car in question is 6 years old and only has 6000km, so the engine is "barely" out of its running period... Could have the engine been abused in the first 1500km before you acquired it?    

North American RON-MOM Ave Octane is equal to RON of 4 to 6 points higher so our 87 same as 91 to 93 in euro system; so our pump 93 is same as RON 97 to 99.  So much for way worse ... as to power output we are held back by a tune homulated fro emissions and mileage that is not worth the expense to change.. has nothing to do with octane limitaions.

[gregs24]

What fuel is common in Italy ? As far as I'm aware Italy is strongly pushing E10 / E15 petrol which is known to cause problems in some engines. Certainly in France most standard fuel is 95-E10 now which I certainly wouldn't use in the Evora - or Mondeo for that matter !

This is what Lotus say about Ethanol

Ethanol E5 & E10 - A mixture of 5% or 10% ethanol (grain alcohol) and unleaded petrol may be used on Evora, but the lower octane rating (typically 93 - 94 RON) will result in slightly reduced performance and economy. If driveability problems are experienced as a result of using ethanol, use 95 RON unleaded petrol. Do not use Ethanol blends with a higher concentration than 10%. Methanol - Do not use fuels containing methanol (wood alcohol). Use of this type of alcohol can result in performance deterioration and damage to critical parts in the fuel system.

 

Edited October 1, 2017 by gregs24

[French Frie]

@gregs24: here in France, almost all the gas stations are offering 95 AND 98 petrol ... sometimes, 95 is now replaced by 95-E10, but 98 is always offered. as an example, here's what was displayed on the Auchan's pump today (was fulling the pick-up, not the Exige !) ... basically, it says that by oct, 24th, 95 petrol will be replaced by 95-E10 ... but as you can see, the 98 fuel is still available !

 

[gregs24]

Sorry I didn't make it clear - yes most offer 98 or 99RON alongside the 95-E10. In fact the price differential between the two is often very small compared to the UK.

Another problem with 95-E10 is the hydrophilic nature of the ethanol which can cause corrosion of fuel systems

 

[Julian73]

US has been using this contaminated E10 gasoline for years and thus cars have been designed to combat the corvine effects of it for years.

[Breeze]

 Given that Lotus have now sold a good number of supercharged V6 cars around the world ( Elise, Exige, Evora S and 400's ) I'm sure that if this really was a question of chocolate engines, we would be hearing about it in endlessly on the various forums, like the famous clutch issue...that didn't affect as many cars as we were led to believe, forums always having the ability to inflate issues by a significant facto.  It has to be something to do with Local conditions here in Italy. V6 Sc Lotus cars are sold in plenty of countries with hot climates..UAE, Australia, Malaysia etc without any problems that we have heard about.

I have also heard, don't know whether it's just folklaw or fact, that some unscrupulous gas stations in Italy have been know to sell lower octane fuel from the higher octane fuel pumps.  A nice little earner I guess, and most people would never know.

[Beady]

I have not been able to add to this topic due to an ongoing warranty claim but I can now confirm first hand experience of piston failure in my (ex) S IPS.

2 pistons like this and third one starting to go, all on same bank of engine at less than 12k miles. This essentially resulted in a replacement engine. More details to follow in a (third party) warranty thread when I get chance to write it up

[au-yt]

Surprising to read about this issue with Toyota engines and personal experience says fuel and the catalytic converter material. Take heart its a cheap engine to rebuild and One of the reasons I bought a 400 is the TOYOTA  motor not in spite of.

Its easy to get peeved off with LOTUS but the cost of compliance of a new engine is beyond LOTUS's means, Geely finance backing may change that. No Engine is perfect and the Japanese engines are better than most.

 

 

[Camber74]

Hello Paul, my failure is exactly like your failure. I would say same issue, and I assume same root cause.

I'll be very interested to know more of your investigation.

about Toyota, I don't believe at all it's an unreliable engine, what is " unreliable" is the application that Lotus did with supercharger, standard thin catalyzers, and I don't know other, that will be hard to investigate.

in fact, this failure mode exist, and despite not so common in this year of investigation I counted several people.for an engine with 100hp/l, in a world close to 200hp/l for sport cars, it is a very poor result overall...

but what suprised me much more than that, is the shamed Lotus reaction (I'm using polite words). Really, I think if you will have a problem with a Zastava, you will be treated with more respect. Totally unacceptable.

[Breeze]

Has any thing been found out yet as to what has caused these problems? I feel very sorry for the guys who have suffered this in Italy, but so far, I still haven’t heard that it’s a problem in other countries. Any updates would be useful for all of us..

[Beady]

I never did discover the root cause.

however a new short motor from lotus is circa £10k supplied but the identical item from Toyota is under £3k 

Didn't put me off .....now in a 400 

[Spinney]

I won't say who, but I know of another guy here in the UK whose engine had to be replaced under warranty due to piston issues with his Evora S. Maybe he will be along to comment himself at some point.

[Camber74]

hello Guys...I changed my Evora S with an Exige 380 in the meantime...but I would say that in the last 6 months there has been at least other 3 engine broken in Italy. all I believe with the same dynamic, cat broken, then pistons failure. I cross fingers, I don't believe that Italy have big impact in this. It's a shame to cross fingers after pay such kind of money in a sport car.

[#84]

The latest input I have on this is that the piston failures definitely are caused by exhaust back pressure from melted pre-cats (as I desribed in my previous post in this thread, it happend twice to me). There was another thread in this forum some weeks ago about a melted pre-cat. I also recently spoke to my exhaust supplier, who had sold several systems to the charge cooled 400/410/430 models as well, after they experienced pre-cat failures. But what I learnt was that while pre-cat failures are common, they do only occasionally cause piston failures. I suppose intake temperature and octane number plays a role in the outcome after a pre-cat failure.

When I experienced this in August 2015, I was told that probably a faulty lambda sensor was to blame for the melted pre-cat. It could never been proven then, but recently one of them suddenly permanently failed in the described fault mode.

[Julian73]

Those preCats are not that close to the exhaust ports, I'm amazed that there is so much valve overlap to be able to suck ceramic matrix back into the engine.

[#84]

@Julian73 I have never heard of any case where the melted ceramic substrate has been sucked into the engine. It is the exhaust back pressure that causes excess temperatures and thereby pre-iginition at high exhaust gas flow, i.e. at high engine rpm.

[snowrx]

This is a classic failure mode for modified Turbo Subaru' engines,  ring land fractures on OEM cast pistons with excess boost/timing leading to detonation.

[Francesco ITA]

Hello guys, I'm here because I just had I think the same problem.

I have a 350 Sport produced in june 2020, and I'm Italian...

The car has 22k km. The break-in was done flawless, it had the first 2000 km check. I've done about 10 trackdays in these two years. Services every 7000 km, exact engine oil used as user's manual suggests... Full stock car. Always warmed up before going to 7000 rpms, always cooled down after 3-4 laps...

I used most of the time 95 RON fuel, only during trackdays I put 100 RON.

So one day of last july 2022, about 500 meters from home, I heard from engine bay a little bang and it started to run bad, not balanced, the MIL came up.
So I took it to dealer and after a few days the response was: piston failure...
Now I'm still waiting news and what will Lotus do to fix this big problem.

I really don't understand what concerns Italy with these failures...
Not sure, but I thought of the KOBE STEEL scandal exploded on 2017, but my car was built on june 2020 (and delivered on september 2020) : https://www.reuters.com/article/us-kobe-steel-scandal-ceo-idUSKBN1GH2SM

 

[BatMobile]

My car explicitly says to only run on 97ron and above.

mine only drinks esso 99ron and if I put in 97ron from BP I’ll always drive a little slower till I can put in the 99.

could it be continued use of 95ron?

[#84]

@Francesco ITA I am really sorry to hear about the engine failure for such a new car. Even though the insurance company and the manufacturer may pay attention to the details you mention, i.e. running in procedure and service intervals, it doesn't have anything to do with this type pf failure. At least if it is caused by pre-ignition / knocking. If so, it is all about temperature in the catalyst/exhaust manifold region and air/fuel mixture. 

Check 1 - Remove the lambda sensors after the catalysts, inspect each catalyst and see if it is damaged. Damage normally start from the end.

Check 2 - Check the lambda sensors, especially the ones before catalysts. Problem here is that they can behave well when at ambient temperature, work well again for some time, and then completely fail. I am not an expert in this topic, but more sophisticated equipment may find the problem. Otherwise you check it with a gas burner and a volt-meter.

Maybe a faulty injector could cause the problem, but most likely it is temperature. When it was discussed in the forum some years ago, my impression was that Italy was over-represented in piston failures and if you combine track days with hot climate and maybe add tracks with higher average engine output, that should increase the probability for this failure to occur. Unfortunately.

[Francesco ITA]

23 hours ago, #84 said:

@Francesco ITA I am really sorry to hear about the engine failure for such a new car. Even though the insurance company and the manufacturer may pay attention to the details you mention, i.e. running in procedure and service intervals, it doesn't have anything to do with this type pf failure. At least if it is caused by pre-ignition / knocking. If so, it is all about temperature in the catalyst/exhaust manifold region and air/fuel mixture. 

Check 1 - Remove the lambda sensors after the catalysts, inspect each catalyst and see if it is damaged. Damage normally start from the end.

Check 2 - Check the lambda sensors, especially the ones before catalysts. Problem here is that they can behave well when at ambient temperature, work well again for some time, and then completely fail. I am not an expert in this topic, but more sophisticated equipment may find the problem. Otherwise you check it with a gas burner and a volt-meter.

Maybe a faulty injector could cause the problem, but most likely it is temperature. When it was discussed in the forum some years ago, my impression was that Italy was over-represented in piston failures and if you combine track days with hot climate and maybe add tracks with higher average engine output, that should increase the probability for this failure to occur. Unfortunately.

Hi, thank you for advices, my car is currently in the hands of service, warranty is not expired.

Really don't know how will finish this case...

I'll keep you informed.

Thanks.

On 23/08/2022 at 20:22, BatMobile said:

My car explicitly says to only run on 97ron and above.

mine only drinks esso 99ron and if I put in 97ron from BP I’ll always drive a little slower till I can put in the 99.

could it be continued use of 95ron?

On the user guide italian version it's written clearly that engine runs on 95ron...

Anyway I don't think that using a low-spec fuel could cause such a damage...

Thanks.