2.0 Failure

[DanW]

If it was the oil, all cylinders would have had signs of the problem. Same if it were a failure in a coating on the cylinders. Something else happened there and it appears to have only happened in that one cylinder.

Whatever it was, my money says it was a defective part somewhere, whether fuel injector or whatever else might cause that. Otherwise we'd see this all the time in the 2.0, and we have not. Many have gone hard miles well past 50k with no issues.

OP, please post up when the official diagnosis is in.

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[AnnDee4444]

But the 2.0 forum said detonation is normal on these engines, and I shouldn’t worry about octane ratings.

Pretty sure that was the 3.6 guys...


One thing I can't seem to find about LSPI is: what is the low speed? 1000 RPM? 2500 RPM? Does anyone know?

 

[VNT]

I e-mailed him, he said no codes and it wasnt pre-ignition, tops of the piston were fine, suspects it ran lean due to injector problem.

 

[gato]

I find it amazing that the engine kept running and the customer drove it in with that amount of piston damage. Sounds like a tough engine. If I am to have a piston failure on the trails, I want to be able to drive it in to the dealer (after a car wash that is) - hey I was driving my grandma to church on Sunday and the engine felt funny

 

[viper88]

Well maybe they are using a real thin iron liner with a plasma coating, like Ford is using on the 5.0 engines. I couldnt find any literature per the construction of the 2.0, but here is a brief on the subject.

I assume the failure must have been with the injection, running lean on that cylinder.

All the ports looked clean, so at least they dont have all the issues of carbon build up on the intake valves from the PCV system.

No one on the forum here that I am aware of would take a peak with a bore scope.


https://www.sae.org/publications/technical-papers/content/2000-05-0069/

There was a old thread of a guy who bought a 2.0 JL with a blown engine. He rebuilt the the motor. He seemed very competent. He had a bunch of pictures in the thread. I will try looking up his thread.

 

[Heimkehr]

Y’all are over my head with this stuff.

But what you describe as LSPI sounds a lot like what ESS does. Low speed, under load, with hot spots.

How does the Engine Stop Start function crosswalk to pre-ignition events?

 

[DanW]

Pretty sure that was the 3.6 guys...


One thing I can't seem to find about LSPI is: what is the low speed? 1000 RPM? 2500 RPM? Does anyone know?

I'm with you. I don't remember there being much discussion of detonation, knocking, or pinging with the 2.0 except for the recall issue they had early on. The 2.0's were suffering from LSPI when they accidentally put the wrong oil in them at the factory, which I think was SN instead of SN+. The difference is that when the 3.6 has it, it is very mild and doesn't have the consequences that it does in a DI/turbo. The fix was to drain and refill with SN+. Now the new SP is even better at preventing it.

I'm not sure where in the RPM band LSPI occurs. That's a great question that I'd love to know, too, out of curiosity. I'm totally guessing, but I'd bet just off idle up to about 1600 rpms. I might be wrong, though.

I can't help but wonder if older SN or even SM oil was put in that engine. Maybe they used some old stock 5w30. If so, they'll see some others come in with the same failure. But again, that's just wild speculation on my part.

 

[DanW]

How does the Engine Stop Start function crosswalk to pre-ignition events?

I doubt it comes into play, if the right oil is in the engine and nothing is broken. Too many 2.0's are running around using ESS with no issue. And again, many with more than 50k miles.

 

[Tank the Jeep]

How does the Engine Stop Start function crosswalk to pre-ignition events?

Low engine speed and fuel added to a hot cylinder under load. I’m no doctor but I play one on tv

 

[Heimkehr]

Low engine speed and fuel added to a hot cylinder under load.

I'd posit there are thousands of Wrangler owners on both sides here: those who disable the ESS function, and those who allow it to work without interruption.

Numbers being of the essence, and if what you propose is accurate, it's worthy to consider why we don't see more threads like this one. As @DanW suggests via my quoted post, I don't think ESS is the culprit here.

I'd say that the likely cause of the damaged piston was lean fueling due to a faulty injector. That said, additional and informed conversation on so-called LSPI events would be helpful, too.

 

[Steve Jennings]

Any chance it was topped up with diesel ?

 

[JL MADDOG]

I assume the failure must have been with the injection, running lean on that cylinder.

That's what my guess is too. Partially clogged injector maybe?

I've seen this on engines with forced induction before and it was usually attributed to a lean condition. Some had considerable carbon deposits that created excess heat in the combustion area. Others were clean as a whistle but had some failure in the fuel delivery system.

It would be interesting to see the head.

 

[AnnDee4444]

I would bet that the eTorque puts less load on the engine during ESS events.

So now I can claim that eTorque is saving my motor from LSPI, right?

 

[Higgs Boson]

LSPI is generally a concern up to about 2500 rpm.

start/stop has nothing to do with it. it's amazing how such an old technology (10 years at least) is still voodoo to so many people. i guess that's what happens when one switches cars slowly or is brand loyal to a product late to the game.

single cylinder failures like this are usually related to a failed part in that cylinder (injector, plug, or even just a defective block, piston, ring, etc). maybe even an install error.

 

[DanW]

LSPI is generally a concern up to about 2500 rpm.

start/stop has nothing to do with it. it's amazing how such an old technology (10 years at least) is still voodoo to so many people. i guess that's what happens when one switches cars slowly or is brand loyal to a product late to the game.

single cylinder failures like this are usually related to a failed part in that cylinder (injector, plug, or even just a defective block, piston, ring, etc). maybe even an install error.

Start/Stop could be 20 years old and I'd still think it is a dumb idea and bad for engine wear. Hopefully the magic coatings they put on the wear components will work. If they do, then my engine might go a million miles since I don't use it. I'll bet it shortens battery life, too.

What's really interesting is when someone has ESS and uses it to save gas, but also uses remote start, letting their engine idle to cool or warm a car, which wastes gas.

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