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My 2000 with just a bit over 350k has been having a relatively minor, but annoying issue. It seems to have a lack of power before a certain RMP depending on how it is being driven. Under extremely light acceleration, it will feel sluggish, but come back to life, with smooth power at 1,500 RPM. Under normal acceleration it will do the same thing, but come back at 1,800 RMP. The problem is most noticeable under heavy acceleration, where it will stumble until it springs to life at 3k RMP. Problem only occurs when completely warmed up. Car idles fine, but has hesitation/vibration when engine is at ~1250 RPM, in neutral or accelerating from a stop.
Using 93 octane gas does give her noticeably more power and low end torque, and increases fuel economy by about 3 or 4... But the boost is still there at all stages
I've read about similar issues with the V6 vvt-i Avalon's and Camrys, but the solutions on those forums didn't work for me or were not the case.
I clean the MAF at every oil change (4.5k), and have checked it with a scanner. Reads within spec at idle and at 2500 RMP without load. Temperature sensor reads 180F +/- 2 depending on the weather.
Things that have been replaced within the last 50k miles (mostly as general maintenance)
~50k New Aisin timing belt kit (installed by mechanic)
~50k New OEM OCV Bank 1 & 2
~50k New OEM knock sensors and wire
~20k New Denso AFR sensors
~1k New OEM push in PCV with OEM Grommet and OEM bank 2 vent hose
~25k New OEM Gas cap to fix P0446, P0441
~5k 6 New Denso spark plugs and OEM gaskets at every point on the intake.
~10k New OEM gas gasket and deep clean of IAC
I don't know what else you can do to the engine. FYI I notice the same thing on my car but I have less than 50,000 miles so it's very minor. What kind of servicing has been done to the transmission?
To my knowledge, it has never been touched (parts replaced). I have records of fluid being drained and filled every 60k miles, until ~290k when I upped it to drain and fill every 20k miles and changed the strainer. Usually the shifts can barely be felt and it works pretty much flawlessly. It does make a faint whine, but the previous owner said its been doing it since at least 150k miles.
Your car is probably the closest example (on the forum) to what these cars were like on the dealership showroom... So that makes me feel a MILLION times better!
I'll probably try that soon. I've just never been able to figure out how to change the rear spark plugs without removing the intake. It comes and goes for me too... That is what is so puzzling to me! Obviously, the engine is capable of running without doing this.
If I were in your shoes I wouldn't want to drive it at all... Then again, if mine had mileage like that, I'd get myself in trouble. I'd end up talking myself into the AVS upgrade, HID conversion and brand new Platinum Edition wheels...
I have a 2000 Lexus ES300, a little over 225,000 miles, it has the same exact issue, it is especially noticeable while accelerating through the highway ramp, it feels like turbo lag, aka a noticeable increase in power after some RPM. I tried diagnosing it, but couldn't find any smoking guns, even after changing the MAF sensor, new A/F sensors and NGK Laser Iridium plugs, I don't see any real improvement in that regard.
My best guess at this point, considering that a lot of those cars have this issue, is that it has to do with the power curve 1MZ-FE engine produces, especially after some wear and tear, here is a very good thread that goes into details comparing 1MZ with previous 3VZ engine..
I have a 2000 Lexus ES300, a little over 225,000 miles, it has the same exact issue, it is especially noticeable while accelerating through the highway ramp, it feels like turbo lag, aka a noticeable increase in power after some RPM. I tried diagnosing it, but couldn't find any smoking guns, even after changing the MAF sensor, new A/F sensors and NGK Laser Iridium plugs, I don't see any real improvement in that regard.
My best guess at this point, considering that a lot of those cars have this issue, is that it has to do with the power curve 1MZ-FE engine produces, especially after some wear and tear, here is a very good thread that goes into details comparing 1MZ with previous 3VZ engine..
Hope this helps and best of luck!
That makes a lot of sense actually... Those charts appear to be for the pre vvt-i engine. This jogs my memory to an article I read a few years ago, about the new for '99 1MZFE. It said something like the engine is supposed to be able to make 80% of hp and 60% of Torque at 1,800 RPM. I haven't been able to find any other dyno chart (for the vvt-i). However I would assume it spikes at 1,500, 1,800, and 3k? That would lead me to believe the gears on the camshafts are most likely (definitely ) worn and imprecise. Resulting in what feels like three engines in one . I've only driven the regular 1MZ just a once or twice, but that particular Solara felt much more peppy and didn't exhibit this issue. It would be interesting to know if any 97-98 owners experience this problem.
I've also thought it could be something to do with the "acoustic" flaps in the intake. I believe they are supposed to open depending on throttle input and RPM. Maybe, the rubber hoses have just become loose enough, to where they do not hold proper vacuum all of the time. So, the two (or three?) butterfly valves just ease from rest to slightly open, instead of snapping shut.
Hmmm, it actually didn't even cross my mind that those are VVT-i cars somehow when I was writing the previous post..
It is interesting how Toyota was keen of 1MZ engine the moment it was first released, and how their rapture was decreasing over the years, finding a VVT-i power graph is a challenge all on its own, below is the best I could find, though I don't think it reflects the real performance..
Originally Posted by BROCKES300
I've also thought it could be something to do with the "acoustic" flaps in the intake. I believe they are supposed to open depending on throttle input and RPM. Maybe, the rubber hoses have just become loose enough, to where they do not hold proper vacuum all of the time. So, the two (or three?) butterfly valves just ease from rest to slightly open, instead of snapping shut.
About the flaps, as far as I know, they were only introduced a generation later in 2002, 3rd-gen didn't have those quite yet, so I would consider those checked off the list of potential causes.. Though it will never hurt to clean the throttle body.
Hmmm, it actually didn't even cross my mind that those are VVT-i cars somehow when I was writing the previous post..
It is interesting how Toyota was keen of 1MZ engine the moment it was first released, and how their rapture was decreasing over the years, finding a VVT-i power graph is a challenge all on its own, below is the best I could find, though I don't think it reflects the real performance..
About the flaps, as far as I know, they were only introduced a generation later in 2002, 3rd-gen didn't have those quite yet, so I would consider those checked off the list of potential causes.. Though it will never hurt to clean the throttle body.
Hope this helps and best of luck!
There does appear to be an increase after a slight decline, at 3k on that graph. Its not really surprising that Toyota began ignoring the 1MZ after some time. It was produced for like 15 years, and (only) saw an increase of about 22hp over that time. Not to mention, if you go back to some of the old forums on the ES page circa '01, the people on here seemed tired with, and disappointed with the implementation of the 1mz on the 4ES. I guess that's why it is such a perfect engine for the RX and ES. Just like everything else about them, their engines are seemingly indestructible, yet just boring and underpowered enough to be ignored and written off by most people.
Maybe "flaps' is the wrong term? There are definitely vacuum activated doors of some sort inside the intake of the 3ES. They are intended to restrict sound from coming back out of the engine, but open to allow for free air flow, under the right conditions.
Here is a video from a former 3ES owner, cutting the intake apart.
Not to mention, if you go back to some of the old forums on the ES page circa '01, the people on here seemed tired with, and disappointed with the implementation of the 1mz on the 4ES. I guess that's why it is such a perfect engine for the RX and ES. Just like everything else about them, their engines are seemingly indestructible, yet just boring and underpowered enough to be ignored and written off by most people.
At least for 2001, I wouldn't really say it was underpowered, at least compared to its counterparts at the time. It was right on par with Honda J engines, which were their main competitors, it could even hold its own with some German competitors, like mid-trim Audi A6 and 5-Series.
Originally Posted by BROCKES300
Maybe "flaps' is the wrong term? There are definitely vacuum activated doors of some sort inside the intake of the 3ES. They are intended to restrict sound from coming back out of the engine, but open to allow for free air flow, under the right conditions.
Ow, that one.. I thought you were referring to the flap that appeared in the next generation, it was mounted even before the air filter, and to be perfectly honest, even to this day, I am still not exactly sure what it is there for..
That particular flap is called ACIS, I actually never considered it to be there for acoustics, I thought its main function is to increase power and torque after a certain RPM by varying the length of the path that air has to travel, that's what was the cause for confusion. This system is actually a little controversial, a lot of people claimed it actually reduced the power and then proceeded to bypass it, but the later dyno readings proved them wrong.. Though with that kind of impressive mileage, it makes sense to clean it out..
I had the same issues with my 137K and counting 99 ES3...until
Hey man I actually was talking with my buddy about my rides shortcomings (I have new Denso Plugs in all my cylinders and had her tuned up about 6 months ago)...he said that on our 20 plus old cars that the actual gas pedal wears out because "most of us" have our right foot hovering on/around the middle of the gas pedal 90% of the time...(Wowzerz! who knew a gas pedal could wear out?!) he advised me to try putting my foot all the way to the top edge or even past the pedal's top when I want that quick "reach back" velocity outta my Lex...
never heard that before so I tried it on my next freeway on-ramp-holy sheeeit!...Lex got us onto 780N with a quickness I mos def wasn't expecting that acceleration without hesitation...so from now on I go "Over the Top"...
I invite you to try it...
04-23-22, 12:24 PM
Lack Of Power and Surging
) worn and imprecise. Resulting in what feels like three engines in one 
. I've only driven the regular 1MZ just a once or twice, but that particular Solara felt much more peppy and didn't exhibit this issue. It would be interesting to know if any 97-98 owners experience this problem.
