dcguy

I can’t be the only one. This has been consistent with every oil change. I get a low load knock at 1% to 3% throttle input maintaining speed, knock sensors go crazy but only after an oil change! Come to find out that the 2UR does not like to be filled past the halfway mark between low and full on the dipstick, otherwise the engine consumes oil and creates knock, however…. every oil change lately no matter where the level is at the knock sensors go off the richter scale rendering the car nearly useless to drive, seems to be getting worse. My oil is not overfull, my aos is empty, and there is no vacuum leaks (though it acts like one) nothing else was touched besides a simple oil and filter change. Personally don’t believe it is tune related. After 200-300 miles car slowly snaps out if it and runs like crazy. Amsoil signature 5-30

I want to understand why new oil is creating knock/detonation it should be the opposite

lobuxracer

iTrader: (2)

This has not been my experience with either of my F cars.

SoulFreak

iTrader: (1)

The same thing started happening to mine three intervals ago. I noticed it right away when I switched from redline to Renewable Lubricants. I just changed the oil two weeks ago. Same thing. I been extremely meticulous with the oil level. Looking back at the history I noticed The Valley plate was resealed at 69k miles. I’m at 86k miles now. Changing oil between 3-4K miles. The only thing I can think of is the knock sensors were messed with during valley plate job. My KCLV will dip into single digits. Then slowly climb back up.

dcguy

Yessir same results, luckily have never had the valley plate done, yet, kclv has made it down to 4 car can barely make it above 55 mph or up a slight hill. Some oil changes are worse than others. Some just pull 5 off the KC for a day and get better shortly after, others are crippling. Have also been meticulous with level. Its almost like new oil has some sort of flammability or creates noxious gases when heated up the first 3-7 times that creates detonation? 2ur design flaw? Our F’s rebuke new oil, why?! Its driving me crazy

SoulFreak

iTrader: (1)

This isn’t a common issue. This my 3rd IS F & I’m certainly learning a lot from this one. The other two I had ran Mobil 1 oil & I don’t remember them having this nuisance. At first I thought it was bad fuel. But I’m using nothing but Shell 93.

dcguy

Yeah, there has to be more out there but very few, Ive had others locally that have had the same issue but was resolved by filling the oil less than 3/4 or close to 1/2 from full on the stick. Also to mention with headers if the dipstick was modified it could result in an improper reading. Another on facebook mentioned he had the same issue when using amsoil but went back to mobil 1 and hasnt happened since. So this may be an oil type thing as well

Rossi

iTrader: (5)

I does not make whole lot of sense to me unless you resetting ECU, disconnecting the battery or such. You are running 5W-30 right?

JT2MA71

iTrader: (7)

Yeah, no issues with both my RC F and IS F. I always fill to the full mark.

SoulFreak

iTrader: (1)

Absolutely not resetting ECU or disconnecting battery at all. As a matter of fact when you reset ecu KCLV defaults to 15. What I’m experiencing it’s KCLV levels in single digits & slowly climb back up to 20-22. Correct, 5w-30. Agreed, it doesn’t make sense. This only happens during oil change.

MileHIFcar

I can echo what OP says about his KCLV tanking after every oil change. We go to weekly car meets so I'm familiar with his situation. We just got back from a long cruise to the Royal Gorge and his KCLV bounced back up to 23+ above 3k but then on the way back it took another hit where is was pulling timing and bogging down to the single digits before recovering again to the low 20's. It's exactly what the title states only after oil changes does this happen to his car and apparently other F's out there are affected if someone pays attention to their KCLV numbers knowing when their car is pulling timing or adding it back in and how the car responds.

This is baffling to say the least🤔

dcguy

Correct would like to add its a rolling downhill snowball effect, once the knock begins it accelerates from -4 to -9 very quicky if you do not change throttle input immediately watching obd fusion like a hawk. The more the learn value takes a hit the more it picks up more knock, single digits come very quickly, took under a minute today to go from 24.3 to 6.4 in 50 mph highway speed. At single digit learn values its nearly impossible to accelerate, as the ecu decides its a great time to start dumping fuel, wideband says .65 lamda (9.5-10 afr) and bogs, have to downshift to finesse the learn value back up then the fueling corrects itself.

93MSB

iTrader: (8)

Mine has been doing this for a while now, however oil level or changing oil doesn't seem to have any effect on its presence. My KCLV can get up to 24.5 and can drop to ~19

I haven't really been able to pinpoint any specific scenario that causes it, I do believe its more prevalent after a left hand turn for whatever that's worth.

I use renewable lubricants 5w30, I have done the valley plate and i had to replace a knock sensor due to the leak, rr tuned but i see this behavior on the stock tune as well

I'm curious if you've also been monitoring misfires? Another thing mine does is show misfires on random cylinders but they never trigger a CEL

SoulFreak

iTrader: (1)

I have OBD Fusion, can you monitor misfires with the app? If so how? I been wondering about misfires, during my idle I can hear what I think it’s misfiring. I changed my OEM plugs recently with brand new OEM ones. It’s still doing the same thing. No CELs. I just have QES exhaust. And I can hear the tone change during idle. It’s a subtle popping sound, not very prevalent but I can hear it change.

dcguy

93MSB thats a good idea! Ill be adding misfires to my list and documenting that as well.
Soulfreak add a digital display its under the add-on of toyota/lexus/scion > engine > total misfire count from there i suppose we could add all 8 cylinders and single some out but have a feeling it would be random

lobuxracer

iTrader: (2)

How many of the problem cars have an AOS?