It seems pretty obvious there is an oil related component in the affected engines that makes enough noise to affect the knock sensors with fresh oil. What that is or why that is remains to be discovered. That said, I've never experienced this with either of the 2UR-GSEs in my garage. AFA engine components, there are two exhaust cam drives and their associated VSVs along with four cam chain tensioners that all have oil pressure applied to enable their operation. It may well be possible these components drain on an oil change, and rattle at the common knock frequencies until they get pressurized sufficiently again after an oil change. Why this only happens after an oil change is the real mystery. It would seem if the problem is drain back, it would happen on every cold start. I also suspect some oils are more likely to have this problem than others since this is not a common fault, witness those here who, like me, do not ever have this problem.

The only oils in my engines have been the OEM fill and "free" initial service from Lexus, Mobil 1 in my IS F, and now Renewable Lubricants 5w-30 PCMO in all my cars. Given the wear numbers I see from Renewable Lubricants, and my propensity for keeping my cars for a very long time, I won't be switching any time soon.

I have had some bad experiences with oils, even those with superior reputations, so it wouldn't surprise me at all if this is related to a particular brand of additive found it some, but not all, motor oils.

 

It would appear that the affected engines are experiencing low speed pre-ignition (LSPI).
LSPI occurs when residual oil on the cylinder walls or ringland space mixes with liquid fuel from direct injectors and reacts chemically to produce a liquid that has a drastically lower octane than either the fuel or the oil, which causes pre-ignition. This mixing doesn't happen with port injection as the fuel is vaporized as it enters the combustion chamber. Research indicates that high concentration of calcium in the oil additive package promotes LSPI while moly suppresses it.
Based on this I propose a theory. It may be that some of our engines which leak more oil than others into the combustion chamber are prone to LSPI if running oil with high enough calcium levels. The reason the problem goes away for some after some miles may be that as the calcium additive depletes with mileage, the calcium concentration drops below the threshold needed for triggering LSPI.
@dcguy you're using amsoil which has low calcium and high moly so this shouldnt be happening. From your profile I understand you're supercharged and running E85, so high combustion chamber pressure plus running rich with E85 may be contributing to LSPI at an even lower calcium threshold than the others?
@SoulFreak you mentioned yours started doing this after switching from redline to Renewable Lubricants. Both oils run high calcium but redline has very high moly while RL has practically zero moly.
@93MSB you also using RL oil.
Contributing factors other than oil additives and the health of the piston rings and chamber walls may be the direct injectors not atomizing the fuel as well as they should causing more washing down of the cylinder walls and pistons with liquid fuel.
It wouldn't hurt to do a leak down test as@lobuxracer suggested and if running high calcium oil switch to an API SP / ILSAC GF-6 or dexos1gen2 or gen 3, or any other oil with no more than 1500 ppm calcium and a decent shot of moly. These latest standards came about to specifically address LSPI in DI engines.
Main source: https://www.youtube.com/live/7n08OX5...weoRF7QVj-YdzO
Skip to minute 37 for the good stuff.

 

I was doing this and 1) worked to stop the KCLV from dropping and 2) raised the KCLV, but this isn't practical to keep doing at all times, thus when I'd go back to regular driving and cruising at a constant throttle position my KCLV would crash.

The issue never came back after fixing my vacuum leak. Either that was the issue or I had enough miles on the oil at that point for the issue to be resolved.

 

Interesting theory. I use Kirkland synthetic 5w-30 which has lower calcium (1200ppm) and average moly (70ppm) per my last analysis.

 

Very thorough @MMI ! Thanks for your reply, this is really interesting, and think this explains it better than just a fluke occurrence, as it’s extremely consistent after every change and slowly dissipates after hundreds of miles, seems to be getting worse with time, I am changing my oil here in the next month or so and plan on changing from amsoil to potentially renewable lubricants, from what I’ve gathered the whole oil market got shaken up with new regulations from ilsac gf-6 (correct me if I’m wrong) and some oils that used to test high no longer do, amsoil included. I plan to update the thread after the next change and document this reoccurring issue

 

Thanks for that info @MMI ! There was only one thing that I experience that contradicts what he said in the video. He says at ~38:10 its more prevalent at lower engine temperatures. I always get more knock feedback when my engine is warmed up at operating temps. Perhaps he means at lower operating temps vs higher temps a racing engine sees?

I'm due for an oil change, taking the info from the video it sounds like for me he would recommend a dexos gen2? Since I'm mostly daily driving with some high performance activity (marathon runner as he describes it).

Is there a source to look up the additive packages in the different oils?

Edit3*
do we have current data on the RLI formula? Looking at Lance's last UOA his calcium and sodium dropped a lot after the 5/14/2022 analysis, still no molybdenum
https://www.clublexus.com/forums/is-...l#post11577620

The last batch of RL I put in my car (7-8months ago) was purchased on 6/26/22, I buy the 5gal pail every 1-1.5years and from that get 2 oil changes at 5k miles intervals. So its possible I could have a batch of an old formula with high calcium and sodium.

Looking at the other UOA's, perhaps the best oil to try to see if symptoms are alleviated is the Quaker State Ultra Durable, it has under 1500ppm calcium, low sodium ~5ppm, and almost double the molybdenum of most others at 150+

or is there a good known molybdenum additive one could add to RLI? BG MOA?

 

I experience the knock feedback at low throttle input where knock is highly unlikely. Someone suggested super-knock previously but I discounted it because everything I read was referring to high load situations.

Do you know under what conditions the1URFSE/2URGSE runs the DI and when it runs port injection?

 

After looking around I've bought a couple jugs of the new Valvoline Restore and Protect. The other two that stood out to me were Amsoil SSO 0-30 and Quaker State Ultimate 5w-30

There is a virgin oil analysis on bobistheoilguy for the new Valvoline here https://bobistheoilguy.com/forums/th...in-uoa.378226/

Results pertaining to LSPI:
Calcium: 1100
Sodium: 2
Molybdenum: 171
Magnesium: 589

I'll be changing my oil in the next few days and let you all know if I see any changes. It could take a couple oil changes to see anything, but I'll probably be changing it sooner because I don't know how its going to handle fuel dilution. Also, if it actually does what it claims (haha) the gunk it loosens up needs to come out.

 

Valvoline is making some interesting claims about the Restore and Protect product. It is irritating that marketing bought good reviews as soon as it came out with "influencer" discount code. There is a BOGO 50% promotion now for purchasing from Valvoline direct, but as of this morning the 5qt R&P 5W-30 is "sold out". Looking forward to UOA results.

 

Last time I did an oil change with Amsoil, was completely undriveable as KCLV dropped like a rock. Drained it, and refilled w Pennzoil Ultra Platinum and never had my KCLV higher. Still occasionally get minor knock detected at really low load but goes back up soon as give it gas. She loves the e85! (supercharged)

 

Forgot to update this on my last oil change
Feb 8th 2024
Mileage 42000ish
Used the Renewal Lubricants 5w30 w OEM filter
https://renewablelube.com/products/b...-shp-0w20-pcmo
https://www.mylparts.com/oem-parts/l...Y4LWdhcw%3D%3D

Used probably 9.5 ish of the 10 quarts
Ran absolutely fine after and still a month later.

 

I've never experienced this problem in 220k miles of operation. I ran Mobil 1 5w-30 for a long time, and have run Renewable Lubricants SHP PCMO for the last 80k miles or so. Never once did the engine not run the same before and after. I suspect some of these engines have poor oil control which is directly related to ring fit at the factory. It is sadly the luck of the draw like so many other details of individual builds. Not all engines are well made, and the factory always defaults to minimizing warranty claims over outright performance. I guess I just got lucky.

 

Same here, I’ve only used Amsoil and never notice any difference in performance after an oil change.

 

I used to use Royal Purple HPS, switched recently to Amsoil SS for the last two changes, zero issues with either.

 

Ok time for an update, I changed my oil at 108k, I have ditched amsoil and have went with renewable lubricants 5-30 race oil. Picked up a new filter Mobil 1 M1C-453A, in this particular change I did only a oil and filter drain and refill. Did not tamper with anything else to keep any variables out of the mix, same tank of fuel as well. Added about 8.8vquarts and was sitting at just a hair above half mark from full on the dipstick after idling for about a minute to pressurize the filter housing etc. As noted previously I never add past 3/4 to full due to consumption issues with some of the 2UR engines. Prior to change the KCLV has stayed at 24.3 for months and hasn't budged, most knock I would see would be in the low -4 and would not hang out long enough to pull the KCLV back. To my surprise it ran amazing after the change took about a 24 mile round trip in stop and go traffic with some highway, monitored on the OBD fusion app the entire time. KC dropped to 24.0 with some very light knock, I was beyond pleased. Nearly updated this thread immediately out of excitement but decided to wait.

Was thrilled to drive the car again next day in the morning and watch the values hold for once! ... Wrong. All hell broke loose. Total KCLV crash, and doesn't show that it's going away anytime soon just as it did before. Each night for 4 days now have been taking the car out for a 64 mile round trip all highway to get in pulls, and to hit on/off ramps for all sorts of different throttle inputs.

Notes: The knock seems to be much more aggressive when the engine has not reached full operating temp, after a cold start, after 20 mins or driving the knock is easier to avoid by changing throttle inputs and watching the OBD fusion, the knocks seems to come in waves, can be maintaining speed at 65 mph and have no knock at multiple throttle inputs, 2 mins later pockets of knock return and very difficult to avoid. The KFV will accelerate very quickly and get wildly out of control if the input is not changed very quickly. I had seen knock as hard as -19.5 at first, unbelievable. KC would get absolutely rocked, rendering any acceleration nearly impossible when the values are slapped down to 4's to 6's. When the KCLV drops into single digits the ECU decides to take the short term fuel trims up in ranges of +15 to +20 to combat knock (I would assume), and just starts dumping fuel. Lamda in the ranges of .60 - .70 at idle or light acceleration. If i don't get the KCLV back up quickly above 10 the long term will lock in the increased fuel trims, then you get stuck in a pit of running rich and the car bogs, knocks and chokes. Nearly all knock at low throttle inputs lambda is at .98 to 1.02 so fueling is not the cause of initial knock but probably plays into factor in single digits and fuel dump. I use lambda because I run e40 mix makes it easy to read AF ratios on the fly, I have a wideband on my dash as well as e85% in the glovebox. So im very familiar with where my AFR's should be as well as my fuel content.
4 days later the most I see is around -10 so it is improving as the oil gets more and more worn (so it seems). To add the infamous tick on the driver side seems to be much more audible with this oil, potential lifter, or maybe even chain slap from the tensioner @MileHIFcar added he believes is the case after hearing it. @lobuxracer Your mention on drainback is something that resonates, as it seems to be the worse right after a cold start. Once I do a few pulls and rip on the car, the KFV takes a sideseat at full/over temps and I can stay in the 22+ range with minimal effort or attention to the OBD app. I did take photos of the filling cap and how it is angled to drop oil directly on top of the timing chain and cam phaser when its filled as designed, I don't believe it would be an issue but does the cam phaser get oil inside of it somehow that is not supposed to happen from normal operation? I'm drawing a ton of theories up on why this only happens directly after an oil change and why it slowly dissipates after hundreds of miles. Here's a couple photos, just wanted to update