[Georgi]

Funny thing just happened to me. Tonight I had to run some errands and when I pulled out of my driveway the noise was really bad. I found that if I hold my foot on the brake, while in drive, and hold the revs at 1250 it was brutal. Way worse than it normally is and not just my usual cold start, same RPM drone. I crawled under to have a look. Theres a huge chunk of ice built up between the gas tank and the exhaust center pipe. Obviously there's no ice on the pipe itself but its resting up against the pipe support. I suspect this ice is causing my nasty rattle right now. I didnt have time to pull it in the garage, jack it up, and knock all the ice off. Around here its supposed to be 3C tomorrow and I'm hoping most of that ice will melt off. If the noise goes away I know thats what caused it. If its still there I'll pull into the garage after work tomorrow and see what else I can see that might be obvious. I too will post back what I find.
That being said I still have the 1250 cold drone.

When did you start having your problem?
Have you tried holding your foot on the gas same as I did and see if you can duplicate it? Dont just rev it up, but hold it at that rev range.
Not sure where you're located but any chance you also might have some sort of ice build up as well?

I am in Toronto. It started last summer and is getting worse. It is an utter disgrace what Toyota are doing

 

[djfelipe]

Hi! I’m from Poland, one of those who has bought iaai auction car after road accident. After long repair process, once I eventually started driving my xle fwd 2015 Sienna I was getting more and more annoyed with this 1250rpm vibrations. It was causing shaking all equipment inside of the car and decreasing enjoyment of driving a lot. My first thought was, well, my car has been repaired maybe not entirely professionally or just because it has suffered an accident. Than I started searching web and luckily found this post. So, I removed the famous bracket and the crazy noise is gone in 90%. That satisfies me, but! Is that bracket really not needed? Can the car operate long term without this part? Any of you has been using your Sienna without it for a longer period? Appreciate any infos, thanks!

Cześć, Napisze po prostu po Polsku. Czy udało się jakby całkowicie wyeliminować to buczenie przy 1250rpm? odkręciłem tłumik od tego mocowania, trochę lepiej jednak w dalszym ciągu buczy - raz mniej - raz więcej. Jeśli uda się odczytać tą odpowiedź to będę wdzięczny za jakieś info - najlepiej na maila [email protected]. Moja sienka tez 15 rok wersja LE Pozdrawiam

 

[Georgi]

Cześć, Napisze po prostu po Polsku. Czy udało się jakby całkowicie wyeliminować to buczenie przy 1250rpm? odkręciłem tłumik od tego mocowania, trochę lepiej jednak w dalszym ciągu buczy - raz mniej - raz więcej. Jeśli uda się odczytać tą odpowiedź to będę wdzięczny za jakieś info - najlepiej na maila [email protected]. Moja sienka tez 15 rok wersja LE Pozdrawiam

You are fixing the symptom. Why is the engine vibrating in the first place at 1250rpm. even when the car is parked? I believe the throttle position sensor has a defect and gives a wrong signal for amount of fuel at the particular opening of the throttle valve, but have no time to test it now. Just a guess. I tried driving the car with higher octane gasoline and it is way better.

 

[djfelipe]

You are fixing the symptom. Why is the engine vibrating in the first place at 1250rpm. even when the car is parked? I believe the throttle position sensor has a defect and gives a wrong signal for amount of fuel at the particular opening of the throttle valve, but have no time to test it now. Just a guess. I tried driving the car with higher octane gasoline and it is way better.

To squize another propan - butan canister I remake original Toyota exhaust and put instead from Chrysler Pacifica 2016 but still have the vibrations .
Here in Poland I'm using 95 octane gasoline but mostly running on LPG - propan-butan.
I will try to cut exhaust pipe and put another flexible exhaust pipe. I'll see what's happen.

 

[Georgi]

To squize another propan - butan canister I remake original Toyota exhaust and put instead from Chrysler Pacifica 2016 but still have the vibrations .
Here in Poland I'm using 95 octane gasoline but mostly running on LPG - propan-butan.
I will try to cut exhaust pipe and put another flexible exhaust pipe. I'll see what's happen.

Still you are treating the symptoms not the real cause of vibration, ask someone to measure the signal coming out of the throttle positioning sensor, how this signal changes at 1250rpm.
This is how to do it:

 

[Therbi]

Dude, what exactly do you want? If you have that drone at around 1200 RPM it has nothing to do with any sensors or fuel type. Its a crap design flaw they never caught during the design phase. My guess, most likely when they dropped the braided front pipe from previous models, probably to save a buck, is when this started, but it wont go away. So live with it or change it. There are several ways to try and cancel out the harmonic imbalance. Here is a thread that has another solution so maybe give this a try.

Engine Vibration

Can you post a link to the Lexus forum that has the fix? Would love to see some pictures of it. And post pics of your fix too please. Its unseasonably mild here all winter so far so the drone isnt nearly as bad. The colder it is the more it drones so I am not nearly as motivated to get off my...

www.siennachat.com

At the end of the day, if you have drone its the harmonic imbalance between the engine and the exhaust creating matching sound waves bouncing off each other. Removing a bracket or adding a damper weight changes the frequencies and that is treating the cause, not the symptom.

If you have some other sort of problem not related to drone then take it to your dealer and ask them to fix it.

 

[Georgi]

Dude, what exactly do you want? If you have that drone at around 1200 RPM it has nothing to do with any sensors or fuel type. Its a crap design flaw they never caught during the design phase. My guess, most likely when they dropped the braided front pipe from previous models, probably to save a buck, is when this started, but it wont go away. So live with it or change it. There are several ways to try and cancel out the harmonic imbalance. Here is a thread that has another solution so maybe give this a try.

Engine Vibration

Can you post a link to the Lexus forum that has the fix? Would love to see some pictures of it. And post pics of your fix too please. Its unseasonably mild here all winter so far so the drone isnt nearly as bad. The colder it is the more it drones so I am not nearly as motivated to get off my...

www.siennachat.com

At the end of the day, if you have drone its the harmonic imbalance between the engine and the exhaust creating matching sound waves bouncing off each other. Removing a bracket or adding a damper weight changes the frequencies and that is treating the cause, not the symptom.

If you have some other sort of problem not related to drone then take it to your dealer and ask them to fix it.

Dude, why do you think it has nothing to do with any sensors? Do you not think that the wrong mixture of fuel and air can make the engine vibrate?

 

[Therbi]

Never said it isnt a sensor problem or couldnt be fuel related, but you're saying you have that distinct 1200 RPM vibration that many have.
Feel free to re read what I wrote above.
If you have drone that has nothing to do with a poorly running engine. Sure bad gas can make your car run like crap, so can many other things, but it doesnt cause drone and higher octane fuel wont remedy harmonic distortion like that. Not sure how else to say it.
Thats why I said if your problem isnt that distinct drone take it to your dealer. If you can replicate it at any time it shouldnt be that hard for them to find the problem.
You said you have a 2019 and have had a problem since last summer so guessing it should have still been under the bumper to bumper warranty, even now you should still have powertrain warranty.
If you have already taken it in what did they say?