LSPI engine damage

[bigj_16]

Originally Posted By: B320i
Maybe there are not reported issues of engine damage now, but I wonder if life expectancy of these engines will be reduced?
As I've repeatedly turned myself purple in the face saying - I'm noticing a helluva lot of late-model, near new cars clattering away on seemingly innocuous, flat roads. I don't even want to know about hills, that is just murder.

An engine that pings very predictably under light driving circumstances surely won't last as long as something that doesn't. OE's need to step up their game and stop claiming these engines can run on regular-grade fuels. Its more than obvious, based on what I'm seeing, that regular grade fuels aren't making life any easier for DI engines.
I've noticed a lot of clatterers, also, especially Subies (and there are a lot of Subies: Colorado State Car), pulling out from a stop. I thought maybe it was the 85 octane gas here.

 

[wemay]

I don't think the sky is falling where this tech is concerned. I see tons of high mileage 2009+ D.I. vehicles on the road. These folks have no idea what direct injection means, nor do they care. They just keep on keeping on in their Ecoboost etc., day after day. Many over 150K miles.

 

[wemay]

...the clatter you hear is the high pressure fuel pump. It's normal.

 

[FZ1]

Originally Posted By: John_K
I thought the whole point of DI was better fuel economy.
The DI's do get better fuel economy......They also,run hotter,less smooth,and make more noise than the multi port engines. Doubt these DI and Boosted engines will last as long as the Multi Ports. Over reaction to CAFE made 'em sacrifice durability for mpg. JMO

 

[WhizkidTN]

Originally Posted By: wemay
Originally Posted By: SR5
Quote:
My theory is just plain old lugging the engine

I'm with you Pim Tac, keep the revs up and stop lugging the engine. These auto boxes need to be a bit more reactive to driving speeds, and not race to the highest gear possible and hold it there as long as possible.

My Opel has a "sport" button for the auto trans. It will hold the gear longer to let the revs climb before changing up a gear. It will also change down sooner if your speed drops too much or you give it more than just gentle accelerator. If you are going down hill with no gas and touch the brakes, it will drop a gear and hold it there until you hit the gas again.

It's auto sport mode feels like my normal mode with a manual trans, so I used it that way every day, same with my wife. We both dislike driving with the auto in "normal" mode.


Funny you mentioned this. My Sonata has three settings, Normal, Eco and Sport. I also drive almost exclusively in Sport for the same reasons, transmission holds the revs higher and longer. But as Pim Tac notes, i wasn't even thinking of this as way to combat deposits (no LSPI in this normally aspirated engine), but it probably helps.


I'd say just drive "with extreme intention"! LOL!

 

[PimTac]

"I'd say just drive "with extreme intention"! LOL!"



I was taught early on to "wind her up". A similar phrase would be not to drive like grandpa. I think these DI and TGDI engines want to run so wind them up. Putting the automatic in sport mode does this in its own way I suppose.

 

[B320i]

Originally Posted By: wemay
...the clatter you hear is the high pressure fuel pump. It's normal.
Sure it is. I know what a ping sounds like. It ain't no fuel pump noise!

 

[Toptierpao]

Quote by John......."I thought the whole point of DI was better fuel economy."

Direct injection is a great technology, however, when they put that technology into cars not too long ago, the engineers did not plan for LSPI and other issues brought on by it. We are the guinea pigs at their expense, a learn as we go ordeal. Direct injection with its high compression, high heat, high cylinder pressures, and low tension springs delivers on better fuel mileage and great power out of 4 cylinder engines, but, comes with a price until they figure it out while slowly improving the breed, which I believe they will.

For now, yes, they reprogram the ecm to run on the rich side to keep LSPI at bay which is laughable as it takes away from one of the touted benefits of DI, fuel economy. So, now the cylinder walls are being washed, especially in cold weather with long idling events and 0WXX oils. Use an inexpensive conventional and yes, even a basic synthetic oil, due to the heat and cylinder pressures these engines produce, it will not take long to break down the oil even in non severe service conditions. The low tension springs will slowly become varnish and coke bound to the point where they degrade and can no longer contain the hellish pressures within the cylinder leading to even more fuel dilution. Remember, these engines are diesel like in nature which means dirty oil compared to what you may be used to in non DI engines.

These engines, even the non turbo DI engines are super hard on oils so use the best oils that you can afford within reason of course. If you use conventional oil in these applications, nix it for it is no match for DI or TDI . Until the car manufacturers GET IT, with newer engines on schedule to run hotter yet, they will again go to ECM’s for a band aid fix. You, however, do not have to wait.

 

[SonofJoe]

I found this is a 2015 Exxon patent relating to oil formulation and LSPI (I've edited it down a bit in an attempt to make it a bit more digestible)....

Fig. 13 shows drive cycle data obtained from a taxi cab field trial. Two different 2.0L L4 TGDI engine types, from different OEMs were driven in a taxi cab city field trial. Engine performance data was collected using the vehicles' OBD-II ports and mapped onto the published engine torque maps for the respective engines.

As published in SAE 201 1-01-0339, engines are specifically prone to LSPI when they operate in a region above 10 bar BMEP and below 3000 rpm engine speed. Therefore, any region of the torque maps for these engines which is bounded by these operating conditions is potentially prone to LSPI. Based on the measured OBD-II data, it can be shown that engines with different calibrations can exhibit different LSPI behavior based on how they are tuned.

Engine Make 1 spends on average 1.67% of its operating time in the LSPI "danger zone" while Engine Make 2 only spends on average 0.17% in a typical taxi cab city drive cycle, even though both engines are 2.0 L inline 4-cylinder TGDI engines. Furthermore, Engine Make 2 has exhibited zero LSPI related field failures, while Engine Make 1 has exhibited multiple failures related to LSPI. This further illustrates the different responsiveness of different engine platforms to LSPI.


Okay, so let me have a go at translating this...

It suggests that taxis, because of the way they operate, are susceptible to LSPI (presumably more so than your average car driver).

Of the two engine types tested, the worst one spent just 1.67% of its engine-on time in the LSPI 'danger area', the better one just 0.17%. It's stated that the worse engine has 'exhibited multiple engine failures' but the way I read this, all of these engines ran for the duration of the trial (while the data was being logged), and none of them catastrophically self-destructed, despite spending time in the 'danger zone'. And let's not forget that the other, better engines also survived.

To me, this puts LSPI into its correct perspective. LSPI doesn't affect all T-GDI engines equally. Also, even in drive cycles that are prone to LSPI, the worst engines are going to spend 98.33% of the time OUTSIDE of the LSPI danger area! And even when they do slip into the danger zone, it's not an automatic death sentence for your engine.

So let's talk about risk...

The first set of rear tyres on my old Toyota Carina lasted for 100,000 miles. Quite remarkable! However, in all of that time, I lived with the risk that running over a nail could instantly end their useful life. Likewise all of the cars I've ever driven have had glass windscreens. Once, a pebble thrown up by a car in front caused my windscreen to crack really badly. Despite it being a somewhat scary event, I continued to drive accepting the (small but measurable) risk that it could happen again. So why is LSPI any different? Before anyone says replacing an engine costs more that replacing a tyre or a windscreen, anyone you gets into a car does so in the full knowledge that there is a small but definable risk that you could get involved in a serious accident and write-off the entire car or even get killed and we STILL accept that risk.

Oh, and ironically, the Exxon patent goes on to say that using a Boronated Ashless Dispersant reduces LSPI. So an additive mod that's been around for thirty years to my knowledge and is a feature of many of today's US oils knocks LSPI on the head. So why all this fuss??? Honestly!

 

[PimTac]

So Exxon Mobil says boron is the key against LSPI? The old school part of me has always preferred a oil with a good slug of molybdenum and boron both. However, Valvoline has neither one and is considered a top oil here. Their newest formulation analysis has yet to be posted so that may change. Castrol has very good boron levels.

Boron seems to be a jack of all trades additive. It's a dispersant and has anti-wear capabilities. Now we can add LSPI killer to the list.

It would be great if PQIA could test the major brands and their dexos gen2 formulations

 

[Virtus_Probi]

Originally Posted By: wemay
Originally Posted By: SR5
Quote:
My theory is just plain old lugging the engine

I'm with you Pim Tac, keep the revs up and stop lugging the engine. These auto boxes need to be a bit more reactive to driving speeds, and not race to the highest gear possible and hold it there as long as possible.

My Opel has a "sport" button for the auto trans. It will hold the gear longer to let the revs climb before changing up a gear. It will also change down sooner if your speed drops too much or you give it more than just gentle accelerator. If you are going down hill with no gas and touch the brakes, it will drop a gear and hold it there until you hit the gas again.

It's auto sport mode feels like my normal mode with a manual trans, so I used it that way every day, same with my wife. We both dislike driving with the auto in "normal" mode.


Funny you mentioned this. My Sonata has three settings, Normal, Eco and Sport. I also drive almost exclusively in Sport for the same reasons, transmission holds the revs higher and longer. But as Pim Tac notes, i wasn't even thinking of this as way to combat deposits (no LSPI in this normally aspirated engine), but it probably helps.


I almost always drive with my CVT in sport auto mode, but I can still use the downshift paddle at any time to force my revs up...I use it a LOT!

 

[wemay]

If TGDi and Di were failing across the board as some on here would have you believe, there wouldn't be a constant march by the OE in that direction. There have been some issues, yes but its proven itself in the vast majority of applications.

 

[PimTac]

Wemay,

Good point. We should be seeing a lot more engine failures especially from owners who are lax in the maintenance and/or drive their vehicles hard and abusive. Yet we do not. Fuel dilution is most likely a bigger issue than LSPI and there is nothing heard about that either except from auto forums and sites like BITOG.

I do find these threads fascinating and educational since my next vehicle will probably have a GDI engine. The Mazda CX-5 is on top of our short list.

 

[SonofJoe]

Originally Posted By: PimTac
So Exxon Mobil says boron is the key against LSPI? The old school part of me has always preferred a oil with a good slug of molybdenum and boron both. However, Valvoline has neither one and is considered a top oil here. Their newest formulation analysis has yet to be posted so that may change. Castrol has very good boron levels.

Boron seems to be a jack of all trades additive. It's a dispersant and has anti-wear capabilities. Now we can add LSPI killer to the list.

It would be great if PQIA could test the major brands and their dexos gen2 formulations



It could be Boron is key or it could be what Boron's doing which is key.

When you make an Ashless Dispersant, typically what you do is react Poly Iso-Butylene (PIB) with Maleic Anhydride to make PIB Succinic Acid (PIBSA). You then react this stuff with a basic Polyamine to make a PIB bis-Succinimide. In simple terms, the PIB end is the oil soluble bit and the Succinimide ends are the polar bits which attach themselves to the otherwise insoluble, chunks of 'gunk' you want to keep dispersed in the oil.

Now these simple Dispersants are great at what they do. However, they can cause unwelcome side-effects. They are very aggressive to the common fluor-elastomers used in engine seals (the highly active nitrogen sites 'pull' fluorine atoms out of the elastomer and cause it to crack). To stop this, you tend to partially post-react the still basic Dispersant with an acid. Now in theory, you could use any old acid to do this but it's common to use Boric Acid (which is where a lot of the Boron on PQIA comes from).

So is Boron helping LSPI because it just does, because it caps off some of the more highly reactive nitrogen bits of the ashless or because the Boronated Ashless is simply that bit heavier than the non-borated equivalent??? If it were the latter, then you could probably substitute something else for Boron and get the same, LSPI-friendly result.

 

[bluesubie]

Originally Posted By: bigj_16
Originally Posted By: Virtus_Probi
Originally Posted By: bigj_16
What is the standard recommended oil for the Subies? 5W-30?. Any special specs?


For the 2.0l turbo, just a synthetic 5W30 API SM/SN or GF4/5 is recommended in the manual.
"Subaru" oil is supposedly made by Idemitsu and good luck finding any hard info about it...I doubt that many US dealers use it for their changes.
That's pretty broad on specs. Interesting.

From what I have seen so far in studies, and this is very preliminary, maybe pre-preliminary

The ideal oil for LSPI prevention would be:
* as high a viscosity as you can get away with,very end of the range for the grade
* as high in zinc as you can get away with, so probably in the 1200 range, so you won't kill emissions stuff
* low in calcium, probably to be subbed with magnesium
* Group V based, with a little Group III thrown in for mixture sake(no IV's)
* A good shot of Moly, maybe 150-ish

Anyone know where I can get some?

Oils available at Subaru dealerships in Japan and allowed in DIT engines are:

Subaru SN/GF5 5W30 (presume this is Idemitsu)*
Subaru ACEA A3/B4 0W30 (IIRC this is ELF/Total)
Subaru Castrol SLX Professional 5W40

https://www.subaru.jp/accessory/engine_oil/engine_oil/

*Google translate says
"A friction modifier (friction modifier) that matches the turbo engine is used".

Our current SN Subaru/Idemitsu does have a bit of moly while the old SM version had around 600 ppm's, IIRC! Reading SOJ's comment reminds me that there is a bit of boron in the current version as well.

 

[bluesubie]

Originally Posted By: wemay
...the clatter you hear is the high pressure fuel pump. It's normal.

HPFP on newer Subies, Genuine Subaru Piston Slap on older Subies.

 

[bigj_16]

Originally Posted By: PimTac
Wemay,

Good point. We should be seeing a lot more engine failures especially from owners who are lax in the maintenance and/or drive their vehicles hard and abusive. Yet we do not. Fuel dilution is most likely a bigger issue than LSPI and there is nothing heard about that either except from auto forums and sites like BITOG.

I do find these threads fascinating and educational since my next vehicle will probably have a GDI engine. The Mazda CX-5 is on top of our short list.

Good point. I hear a lot about Ecoboost fuel dilution, but haven't heard much if anything about Ecoboost LSPI. Other than Ford pursuing LSPI tests for GF-6/SN+

 

[Whimsey]

Originally Posted By: bigj_16

Good point. I hear a lot about Ecoboost fuel dilution, but haven't heard much if anything about Ecoboost LSPI. Other than Ford pursuing LSPI tests for GF-6/SN+


With over 12,000 miles on our 2017 2.3 EcoBoost Explorer I can honestly say that I've heard no pinging or knocking when the engine is running at 1,300-1,400 rpm in the 45-50 mph range. Though I would qualify that as "lugging". My first UOA of 7,000 miles, posted here, also had no indication of fuel dilution in the oil. Though the mileage was accumulated over 2 months and the vast majority was high speed hot temps driving. I used Mobil 1 5W-30 which seems to be good for controlling LSPI by it's make up. I'm currently running MotorCraft 5W-30 synthetic blend oil for 5,000 miles of "everyday" driving. I'll do an UOA on that run to see how it fairs out.

Whimsey

 

[Virtus_Probi]

Originally Posted By: wemay
If TGDi and Di were failing across the board as some on here would have you believe, there wouldn't be a constant march by the OE in that direction. There have been some issues, yes but its proven itself in the vast majority of applications.


It's a new technology, at least for mass market applications, and there have been some teething issues. Some engines, probably a fairly low percentage, have fallen by the wayside, but strategies to attack these problems through engine design, ECU programming, and fluid formulation are moving along well. I'm sure plenty of people in the early 1900s were laughing at the owners of fragile early automobiles when their horses worked so well, and troubles with early fuel injection made carburetors look like they weren't so bad...I sure don't miss trying to start a carbureted engine in the cold, do you?

 

[bigj_16]

Last carburetor car I had was a 1980 Chevy Citation 2.8. Although it was only a couple years old when I got it, that thing was a major [censored] to start in the cold.