Interesting quasi-LSPI observation with an SN PLUS oil

[Gokhan]

My 1985 Corolla 4A-LC engine occasionally experiences light pinging, especially climbing a gentle hill, when the transmission shifts to overdrive at low throttle and low speed (approximately 41+ MPH, the lowest speed for overdrive). This happens especially when the ignition timing is advanced, which makes the spark plugs run hotter. I like to keep the ignition timing about 4° more advanced than the factory spec. See this YouTube video explaining how advancing timing could increase the spark-plug firing-end temperature and cause preignition.



Interestingly, this only happens at low speeds -- when the transmission shifts to overdrive at low throttle. I also experienced the exactly same phenomenon regularly on a 2009 Corolla 2ZR-FE engine. If this is preignition, which probably is, it's certainly not as violent and damaging as low-speed preignition (LSPI) that happens in turbo gasoline direct-injection (TGDI) engines. Nevertheless, it does only happen at low speeds and there seems to be some similarity in certain aspects, even though the two phenomenons otherwise dramatically differ. Some people strongly disputed that when I suggested it last time.

Now, here is the interesting thing. I've started running the PAO-based Mobil 1 Extended Performance 0W-20 SN PLUS. I'm delighted that my engine runs extremely well with it -- as smooth and efficient as it can be, the engine sounding and feeling like clockwork. I don't think I've had any other oil come close. I've tried to create some pinging events but I have been unsuccessful. Has the SN PLUS actually prevented the occurrence of possibly preignition-related pinging in my engine? It could well be the case. If that's the case, then SN PLUS oils are well worth it in any kind of engine, regardless of whether they are TGDI or not. It will also be interesting how the car will do at the low-speed dyno testing (15 MPH) of California emissions this fall, which is something it always struggles at because I set the ignition at an extra 4° advanced. It will be great if it actually helps reduce the emissions despite the more advanced timing. Interestingly, it does better in the higher-speed (25 MPH) dyno test; so, it could be somewhat preignition related.

Has anyone seen similar benefits using SN PLUS oils, which have reduced calcium and added magnesium?

 

[wemay]

Thanks for posting. It's always interesting to see real time results in action. If that really is the case here, it would be a huge win for everyone.

 

[ka9mnx]

I would think the Mobil1 is keeping your cylinder temperatures lower than other oils thus preventing pre-ignition or detonation.

 

[Triple_Se7en]

Gokhan
You are comparing 0W20 Mobil-1 EP to something you never used before. Not a fair test, since you claimed not using SN Plus prior.
Run that test using a Dex1/G2 SN Plus oil of a different brand. If results are the same....
Run a 3rd test using 5W20
If results are the same, run a 4th test using 5w30.
Might take you a couple years to complete and by-then G6 will be rolling. So it all may be for naught.

On a side note, recent posts or threads (don;t remember) said researchers concluded PAO is the worst for LSPI symptoms. That Group II+ may be the best, followed by Group III. Find yourself a Group II+synblend like Quaker State 5w20 in Dexos1/G2 and SN Plus and run that for comparison. I'd like to know your findings.

 

[StevieC]

It could also be that your timing is just a tad too advanced and the oil is just keeping it under the threshold where a degree or two retarded might do the same thing.
Does this vehicle have an EGR valve? If this is partially clogged it can cause pinging under load as well.

 

[cristo]

Originally Posted by ka9mnx
I would think the Mobil1 is keeping your cylinder temperatures lower than other oils thus preventing pre-ignition or detonation.


Actually, the property of SN Plus oils
that purportedly reduces LSPI is
reduction of oil droplets entering
the combustion chamber rather
than lower temperatures, partly by
reducing calcium and increasing
magnesium in the additive package.

 

[Triple_Se7en]

Castrol Edge SN PLus Dex1/G2 (black bottle UOA/VOA here) shows the highest levels of Magnesium used. Hoping to see a Castrol Edge EP VOA/UOA soon.

Researchers (my above mention) say enriched PAO oils do not help. That Group 2 + 3 are better served with LSPI.
Nice to see Gokham do his own research and every little bit helps.
Thank you for your findings Gokham. Your imput here is valuable.

 

[PimTac]

Sounds like lugging the engine to me.

 

[ka9mnx]

Originally Posted by cristo
Originally Posted by ka9mnx
I would think the Mobil1 is keeping your cylinder temperatures lower than other oils thus preventing pre-ignition or detonation.


Actually, the property of SN Plus oils
that purportedly reduces LSPI is
reduction of oil droplets entering
the combustion chamber rather
than lower temperatures, partly by
reducing calcium and increasing
magnesium in the additive package.

He is not experiencing LSPI. His problem is too much timing advance.

 

[Mainia]

Originally Posted by Triple_Se7en
Gokhan
You are comparing 0W20 Mobil-1 EP to something you never used before. Not a fair test, since you claimed not using SN Plus prior.
Run that test using a Dex1/G2 SN Plus oil of a different brand. If results are the same....
Run a 3rd test using 5W20
If results are the same, run a 4th test using 5w30.
Might take you a couple years to complete and by-then G6 will be rolling. So it all may be for naught.

On a side note, recent posts or threads (don;t remember) said researchers concluded PAO is the worst for LSPI symptoms. That Group II+ may be the best, followed by Group III. Find yourself a Group II+synblend like Quaker State 5w20 in Dexos1/G2 and SN Plus and run that for comparison. I'd like to know your findings.



I thought group 5 ester was the best. So Redline Euro 5w-30 has 1,600 ppm of calcium, which is far less then their other 3,000 calcium oils which is 200 away from Amsoil's 1,400 calcium and they say they are 100% in the speced test. Add Redline's very high moly and group 5 ester and Redline could be one of the better anti-LSPI oil's out there I would bet.

.

 

[claluja]

Originally Posted by Triple_Se7en
Nice to see Gokham do his own research and every little bit helps.
Thank you for your findings Gokham. Your imput here is valuable.


x2

 

[1JZ_E46]

SN+ has not solved the light-load pinging issue I experience with my X5, unfortunately. The pinging is actually worse if the engine is in too low of a gear for a light engine load and it pings. Once it upshifts and the engine is more loaded, the pinging stops. I'm not overly concerned about it since it doesn't ping under load, and therefore it's not creating huge pressure spikes like an LSPI event does.

 

[PimTac]

Originally Posted by Mainia
Originally Posted by Triple_Se7en
Gokhan
You are comparing 0W20 Mobil-1 EP to something you never used before. Not a fair test, since you claimed not using SN Plus prior.
Run that test using a Dex1/G2 SN Plus oil of a different brand. If results are the same....
Run a 3rd test using 5W20
If results are the same, run a 4th test using 5w30.
Might take you a couple years to complete and by-then G6 will be rolling. So it all may be for naught.

On a side note, recent posts or threads (don;t remember) said researchers concluded PAO is the worst for LSPI symptoms. That Group II+ may be the best, followed by Group III. Find yourself a Group II+synblend like Quaker State 5w20 in Dexos1/G2 and SN Plus and run that for comparison. I'd like to know your findings.



I thought group 5 ester was the best. So Redline Euro 5w-30 has 1,600 ppm of calcium, which is far less then their other 3,000 calcium oils which is 200 away from Amsoil's 1,400 calcium and they say they are 100% in the speced test. Add Redline's very high moly and group 5 ester and Redline could be one of the better anti-LSPI oil's out there I would bet.

.




How much Group 5 ester is in Redline?

 

[dailydriver]

Originally Posted by Triple_Se7en
Researchers (my above mention) say enriched PAO oils do not help. That Group 2 + 3 are better served with LSPI.



That may be so, but some of us turbo GDI owners (with manual gearboxes to overcome some of the onsets/causes of LSPI) are concerned with/desire the other PAO/POE base stock oils' qualities/benefits besides exclusively possible(??) LSPI causality.

 

[dailydriver]

Originally Posted by Mainia
I thought group 5 ester was the best. So Redline Euro 5w-30 has 1,600 ppm of calcium, which is far less then their other 3,000 calcium oils which is 200 away from Amsoil's 1,400 calcium and they say they are 100% in the speced test. Add Redline's very high moly and group 5 ester and Redline could be one of the better anti-LSPI oil's out there I would bet.


As I've stated in another thread, IF they formulated an oil with the same high levels of moly (and even ZDDP) as their NON-Euro/low SAPS oils, but with MUCH higher magnesium, and even LOWER than the above stated 1600 PPM levels of calcium, I would use it in less than a heartbeat, yup even if it did not contain all that much POE in the base stock mix, (which so many on here LAMBASTE it for).

 

[CarbonSteel]

Originally Posted by ka9mnx
He is not experiencing LSPI. His problem is too much timing advance.
Exactly! Since when will a 1985 "anything" need an SN+ oil to compensate for LSPI? Most 80's engines did not develop enough HP or compression to get out of their own way, much less consistently experience LSPI. Subjectivity and confirmation bias at its finest.

 

[s2krunner]

LSPI is only issue with turbocharger vehicles. I think your motor just knocking on hills.

 

[Shannow]

Advancing the timing to the point of incipient detonation is NOT an LSPI test platform.

Throw a cup of gear lube in a full tank and see what real pre-ignition is.

 

[caprice_2nv]

Originally Posted by s2krunner
LSPI is only issue with turbocharger vehicles. I think your motor just knocking on hills.


"Pinging" is usually pre ignition, and often occurs at low speed/high load. It happens in my 83 Caprice also and I checked and my EGR valve is completely dead. The reduced it by retarding the timing. It was like 6 degrees over spec and now it's only 1.5 degrees advanced.

How do you not call it lspi whether it is caused by timing over advanced, carbon buildup, high temperature, etc. There are many different causes of it. GDI and turbo engines are more prone to it. How do you say it isn't called lspi if it's not a GDI or Turbo, or it could be reduced by retarding the timing? That makes no sense to me.

His car could be a combination of the timing being slightly advanced, some carbon buildup on the valves, maybe a bit of buildup in the EGR passages also.

 

[OVERKILL]

Originally Posted by caprice_2nv
Originally Posted by s2krunner
LSPI is only issue with turbocharger vehicles. I think your motor just knocking on hills.


"Pinging" is usually pre ignition, and often occurs at low speed/high load. It happens in my 83 Caprice also and I checked and my EGR valve is completely dead. The reduced it by retarding the timing. It was like 6 degrees over spec and now it's only 1.5 degrees advanced.

How do you not call it lspi whether it is caused by timing over advanced, carbon buildup, high temperature, etc. There are many different causes of it. GDI and turbo engines are more prone to it. How do you say it isn't called lspi if it's not a GDI or Turbo, or it could be reduced by retarding the timing? That makes no sense to me.

His car could be a combination of the timing being slightly advanced, some carbon buildup on the valves, maybe a bit of buildup in the EGR passages also.


They are two separate phenomena.

-Pinging/knock/detonation is generally caused by too low an octane rating or too much ignition timing and the result is that "pockets" of air/fuel ignite when they aren't supposed to making a "ping" or "knock" sound
-Pre-ignition is generally caused by combustion chamber deposits, running too hot a plug or oil droplets causing the commencement of an ignition event prior to when it was meant to occur. Your old vehicles, if they've ever "run on" would be experiencing pre-ignition.

LSPI is a massively more severe version of the 2nd scenario where at low engine speed in a forced induction direct injection engine something causes the air/fuel mixture to be ignited before it is supposed to causing a severe explosive event that can severely damage the engine.