2.0 Failure

[Higgs Boson]

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.

The issue with that perspective is that it doesn't cause engine wear. It only works when hot, when oil is still circulated, turns off loaded components, measures piston locations, precise direct injection to continue combustion events in perfect order, etc etc. Many systems don't even use the starter motor to crank it back up. They use a separate battery also to power components when the alternator isn't spinning.

Extra rich fueling, no lubrication, etc etc are non issues and there is no extra wear. Your engine will not go a million miles whether you use it or not. In fact, it might last longer if you do use it since you have less piston travel per hour driven ie less idling (idling is bad for your engine).

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[AnnDee4444]

LSPI is generally a concern up to about 2500 rpm.

start/stop has nothing to do with it.

I bet eTorrque does reduce the average load though.

Also I've been wondering if this has more to do with piston speed than RPM.

 

[oceanblue2019]

Have a friend who is a tech, replacing a 2.0 Turbo engine in a Cherokee with 58K. Car was always serviced and engine internals look clean.

He had it pulled from the car and had it in his stall, waiting on the new engine. The good news is there was no carbon or build up on the valves. The bad news is that one of the pistons was melted down and the lands collapsed/ melted on one side , the intake port side. The car came in running poorly and he test drove and did compression and #2 cylinder was dead. I guess they are putting in new engine, turbo and injectors.

The other thing he also told me was these 2.0 engines do not have iron liners, I guess they use aluminum with a coating on the cylinder walls. He said the cylinder wall was worn thru to the aluminum on the dead cylinder.

Something caused the top piston land to break and caused this.

Typically detonation either from bad gas or too much boost.

 

[AnnDee4444]

Something caused the top piston land to break and caused this.

Typically detonation either from bad gas or too much boost.

I broke a ring land off at high RPM from bad fuel tuning once. It was on a naturally aspirated single cylinder with port injection & electronic ignition. Amazingly the motor still ran OK, but had quite a bit of blow-by at high loads.

Too little fuel from a clogged injector could run lean (hot) and melt the piston. Too much fuel from a broken injector could fuel-wash the cylinder, washing the oil away and causing too much friction. Either of these scenarios could be plausible for a completely stock 2.0.

 

[DanW]

The issue with that perspective is that it doesn't cause engine wear. It only works when hot, when oil is still circulated, turns off loaded components, measures piston locations, precise direct injection to continue combustion events in perfect order, etc etc. Many systems don't even use the starter motor to crank it back up. They use a separate battery also to power components when the alternator isn't spinning.

Extra rich fueling, no lubrication, etc etc are non issues and there is no extra wear. Your engine will not go a million miles whether you use it or not. In fact, it might last longer if you do use it since you have less piston travel per hour driven ie less idling (idling is bad for your engine).

Straight from the mouth of one of the original Pentastar design team: "Don't use ESS. I believe it will accelerate wear." He did go on to say that they applied protective coatings on wear parts but is not yet convinced they are effective.

He also explained that moving parts, at a certain speed, start to ride on a film of oil. But when not up to speed, there is metal to metal contact, even when oil is fully present. He said the timing chain has to be above 1500 rpm to go hydraulic, or get to where it is riding on a cushion of oil. Below that, there is metal contact. He said even hot, stopping and starting is worse than idling.

I'll take his word for it. He told me that if it was his engine, he would not use it.

I hope the coatings work. Because if they do, I might have a million mile engine. But I probably wouldn't live to see that. TIme will tell.

In the meantime, it doesn't save me enough gas to bother, anyway. If I drove more stop and go, it might.

I'm also unsure of its effect on the life of the batteries. I see many JL's replacing bad batteries at 3 years. But that could also be the cheap OEM batteries. Mine were both still strong at the 3.3 year mark. But I replaced them anyway, as a precaution before a big off-road trip. I'd have been curious as to how long they would have gone.

How about wear on the starter? Yes, they allegedly used a better starter, but if that's the case, without ESS it should last much longer. Besides, the starter sounds to me EXACTLY the same as my cousin's 2018 JK with the previous gen Penatstar without ESS.

I'm no expert. But I think the guy who designed the gen 1 engine is. If he's wrong, there's no harm done.

 

[Steve JLUR]

Geez...I thought cylinder coatings went the way of the dodo when the Chevy Vega disappeared. Curious as to how that was not making enough noise that the owner did not realize there was something seriously wrong.

Nikasil - https://en.wikipedia.org/wiki/Nikasil

Germans use it a lot.

 

[Heimkehr]

Straight from the mouth of one of the original Pentastar design team: "Don't use ESS. I believe it will accelerate wear."

He also explained that moving parts, at a certain speed, start to ride on a film of oil. But when not up to speed, there is metal to metal contact, even when oil is fully present. He said the timing chain has to be above 1500 rpm to go hydraulic, or get to where it is riding on a cushion of oil. Below that, there is metal contact.

When rollin' down Highway 41, in 8th gear and with the cruise control holding me steady, I'm barely turning 1,200 revolutions per minute.

I've the 2.0T Hurricane, not the Pentastar. I wonder if the timing chain concern still applies.

 

[DanW]

When rollin' down Highway 41, in 8th gear and with the cruise control holding me steady, I'm barely turning 1,200 revolutions per minute.

I've the 2.0T Hurricane, not the Pentastar. I wonder if the timing chain concern still applies.

I would not call it a concern. Just more wear than at higher rpm. I'm not sure if it was Pentastar specific, either. I'll ask him when I get a chance. He'll probably say it is likely same on other engines, but certain on the Pentastar because he is so familiar with it.

He spoke in terms of making the Pentastar last to its potential, in the context of one that went viral for hitting over 640k miles. He said neglected and abused Pentastars make it to 200k all the time. The context was because I asked him what to do and not to do to get to half a million miles.

Funny, I asked him if FCA/Stellantis would give someone a new one if someone hit 1,000,000 miles with one, like Nissan just did with a Frontier owner. He said no because they knew of several that had already achieved that. He did say that they used to give out badges to people who hit 200k, 300k, and 500k miles, but they don't do that anymore. They just congratulate you nowadays, Lol.

But back to your 2.0. I wouldn't worry about it. While it may be at low rpm, it probably is not working very hard, either, when cruising.

The Pentastar that hit 640k was mostly highway driven. If he idled a lot and wore it out at 300k, I'd bet he wouldn't complain. Interestingly, it was the timing chain that was worn (stretched) and the timing chain guides broke. The valve train, pistons, bearings, etc, showed very little wear, if any. He did 7k oil changes with mostly Mobil 1 and some Valvoline synthetic oils.

I did not mean to imply that these things would croak at 100k if you use ESS. Only that they would wear quicker. But hey, those coatings might just work, too!

Btw, I think that 2.0 is proving itself to be a great engine. I think it has shown to be very powerful and very reliable. My money says it will last a long time, too, if maintained as it should be.

Truth is, at the rate I put miles on Jeeps, I won't live to get it to 500k.

 

[CptFloridaMan]

When rollin' down Highway 41, in 8th gear and with the cruise control holding me steady, I'm barely turning 1,200 revolutions per minute.

I've the 2.0T Hurricane, not the Pentastar. I wonder if the timing chain concern still applies.

I don’t think it applies. We have an electronic oil pump. And depending on load, mine will go from 17psi to 30-40psi at highway speeds at 70mph in 8th gear around 1.5k.

 

[VNT]

Hi

Happened to visit the store this morning and my pal who worked on this had the turbo on the bench, note they are installing a new turbo which they are waiting on. I took a quick peak, and the exhaust wheel looked good, no carbon or anything on the exhaust side, no slop in the cartridge and the puck for the wastegate opening operated nice and free, also it is controled by an electric device to open/close. I am used to vacuum cans on my old Shelby Dodges and PT GTs to control the wastegate movement and external solenoids to control the vaccum on the cans.

 

[AnnDee4444]

no carbon or anything on the exhaust side

Did you happen to look at the intake side?

 

[VNT]

I'll swing buy tomorrow and take a peak.

 

[VNT]

Hi

I took a peak it was perfectly clean on the entrance and exit of the compressor housing.

The TB looked like it had some deposits on the throttle blade, but some PM once in a while to clean the TB would probably prevent that, as I recall the car had 60K miles or so.

The underside of the intake had the water intercooler and there are some fittings and hoses, so another PITA to deal with at 100K when one should change all the hoses and plastic connectors.

 

[srt20]

When rollin' down Highway 41, in 8th gear and with the cruise control holding me steady, I'm barely turning 1,200 revolutions per minute.

I've the 2.0T Hurricane, not the Pentastar. I wonder if the timing chain concern still applies.

Both the 3.6 and the 2.0T have electric oil pumps. The under 1500 rpm thing doesn't make any sense at all for either engine.

 

[Heimkehr]

Both the 3.6 and the 2.0T have electric oil pumps. The under 1500 rpm thing doesn't make any sense at all for either engine.

That was my impression, thus the original inquiry.

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