2012 ISF, 52k miles. Purchased with RR Racing larger tuned intake and catless PPE unequal length headers, Borla catback, blue HPS intake elbow. Car ran fine and honestly great for nearly 2k miles. Great MPG, great performance, no weird sounds. Headers hiss a bit, but I'm told it's normal. Had an 08 with 99k miles and tune/exhaust before this and never had a single issue other than valley plate leak.

Car is now sometimes bogging, has jerky or hesitant acceleration, tries to stay in higher gears and doesn’t want to downshift unless nearly WOT or in manual mode. Hearing slight engine ticking that isn’t consistent, near front of the motor/cam gear motors. Sometimes at 1500-2500 there is a whistle sound coming from engine, almost like a vacuum. No CEL’s on or in the history.

Detailed story:
Last week on 9/30 I went to my ISF mechanic at a toyota dealer. He changed the engine oil with Mobil1 full synthetic 5w-30, the differential oil with redline, reset the transmission(hoping for slightly improved shifts), and swapped out the HPS intake elbow for the RR Racing CF one. Same size elbow, just engine bling but the intake does come with a hose and small KnN filter to delete the two intake breather vents. Engine oil bottom cover was on very tight before new oil put on, but otherwise fine. No fluids are leaking.

I get home about 25 miles away from the mechanic and the car starts acting a bit boggy and jerky. At 2K it takes quite a bit of effort and gas to get it to downshift. Standing in park or neutral it revs up just fine. It shifts fine in manual mode. Sometimes it is jerky and sometimes it is not. I tried launching it and I tried driving like normal, and it comes and goes. I figure that it is the intake elbow so I swap it back and check all connections and hoses. After removing the negative battery terminal and basically resetting the ECU and KCLV down to 15, The car seems to run better in all conditions and KCLV jumps to 21-22 after 20 minute ride. I figure it’s an intake that just needs the AOS also to work as someone recommended it. But the next morning it starts up again seemingly an issue after I drive it on the highway for about 5 miles. When the car is warmed up sometimes an inconsistent tapping/ticking sound comes and goes. I think maybe bad gas so I put in some Lucas octane booster and fresh 93. Before and after both fuels used were Shell 93. Thought maybe transmission was reset incorrectly or diff fluid changed wrong, but neither seem to be an issue as it shifts fine and has no leaks and doesn’t explain the engine ticking sound. Car revs fine in park and neutral though.

I swing it by mechanic to see if it’s a pulley or water pump sound and it’s not. I take it to the local Lexus dealership and after 2 hours and several days of having it and driving it overnight they basically want me to swap it all back to stock . Tech mentioned maybe something with an actuator and the AFR is all over the place on the dash cam, but with no cats and no CEL’s they can’t diagnose. The head foreman basically tells me I’ve modded it to the point with the reflash that even if I swap the cats and intake and software back to stock, they won’t touch it unless there is a new computer put in. They are worried since the tune hides the catless headers it could be seeing or hiding other stuff. I offer to swap the intake back to OEM and reflash back to stock, and in his words he doesn't know what I did to the computer and he won't have his techs touch it any longer unless it's back to OEM. It was honestly a very poor experience dealing with the head mechanic there..

I picked up the car and it ran fine around town, then poorly on the highway with KCLV dropping from 20 to then down to 5-7 then gradually back to 17. By the time I got to another shop 20 miles away it was back at 23 and driving perfect. Still makes the sound but not as loud and comes and goes. Car is at the shop right now getting new spark plugs and compression/leak down test and MAF and diagnostic. If issue still exists I will swap tuned intake back to OEM and reflash to stock to see if it helps diagnose.

I have been told by some maybe something in the motor, valve springs, or cam motor gears, or VVT, or actuators or MAF or evap vsv switching on and off. Maybe the oil type used was an issue, compared to what they had before? Saw similar noises and people used 0w-30 and had success? I've been told by many that the motor is bulletproof and even with any issue it's will adjust and protect itself. Some first guesses at water pump or idler pulley seem wrong since the noise is different. I also saw Lobuxracer’s post about it possibly being a TSB https://st.club-lexus.ru/attach/u/4b...a831eca731.pdf for the timing chain in Europe. But as I understand his sound was only during warming up, though his is loud but sounds similar. I don't think it's the intake and my bet is on a bad sensor somewhere or something loose or broken causing the timing to adjust too much. But not sure..

So TLDR: No CEL’s, low miles, ran fine until some maintenance done and now bogginess and terrible KCLV comes and goes, especially after being on highway for a few miles.

https://youtu.be/4TIElu0xUyk

 

Talk to Rafi at RR Racing. I remember him saying something about the MAF being turned a certain way. Also, do you have a RR Racing tune on the ECU since your using their air box and intake tube? If not thats a issue as you need one with that intake set up

 

Thanks for the reply. I have been keeping Rafi and Sean up to date. I have the tune. For what it's worth I don't think it's their intake or their tune that's the issue. Perhaps it needs to be retuned, but I've pretty much put the car back like I bought it and still experiencing this randomly.
If this shop can't figure it out, I may have to tow it to RR, luckily less than 150 miles away.

 

I would send it to RR because I’m terrible at Diag. Sorry to hear.

how are you tracking your KCLV?

 

Have you considered swapping out the MAF?

Relatively easy swap, and it might explain swings in AFRs?

 

New MAF was purchased yesterday and is getting swapped today. Hoping that is it and spark plugs needed replacement anyways at 60k and I had them so shop is doing both.
As far as KCLV, I use OBDFusion iPhone app, and also have a tech stream laptop, though OBDFusion is much quicker and easier to use.

 

I’m having a similar issue but with no unusual noises. Same mods as well. The kclv drop occurs during very light throttle application at 1500-2500 rpm - easiest to see on the highway going down hills. Only seems to happen once fully warmed up 1hr+ of runtime.
Fyi I changed my MAF but symptoms remain.
I wonder if the knock sensors are picking up something there that it thinks is knock... exhaust leak?

 

Just got compression test back

 

Time for that RR supercharger..I bet it will fix your issue.

 

Yep because it eliminates the tuned intake....problem solved

 

Is that considered good compression?

 

So far everyone has said yes.

 

Cars been at the shop for 3 days and they said it ran fine. Nothing was done besides compression/spark plugs. Even kept MAF it had. Picked up car and KCLV was at 18, after a few miles it went up to 25.5 and stayed above 23. Drove an hour home the long way and zero issues. Pulls better than before the issues started. Not sure what to do other than wait for something to pop up.

guess I’m installing my bazooka axleback tomorrow.

 

Is there a known issue with RRRacing tuned intake?

 

Not necessarily, but some members here have had issues with the intake usually with the MAF sensor positioning in the pipe etc.... and some could not get it resolved and went back to the stock intake. I think the cases have been isolated but no explanation why some have had some issues and the majority of others have not me included. I have had the intake since it was introduced and it has been flawless for me.

I was just saying it would be a perfect excuse to get the RR S/C