RX - 4th Gen (2016-2022) Discussion topics related to the 2016 and up RX350 and RX450h models

2016 RX 350 Excessive noise and vibration

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Old 04-08-24, 09:47 AM
  #2176  
OReliable
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Back from the dealer for the updated TSB that includes the 2022 rx350. Made no difference LOL.

Will be putting back my weight in front of the flexible joint (engine side). Adding photo for reference.

Old 07-15-24, 01:02 PM
  #2177  
Stans
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This might help someone so here we go:
One of my RX's (I own 2 of them) had this pretty awful droning noise. I tried playing with weights adding them to different spots on the pipe which did not make a huge difference. So I decided to take it to Lexus. As expected they installed the updated midpipe with weight attached which reduced the drone a lot to my surprise... I lived with it for a few months and after driving the car in different conditions I realized that the drone was reduced but it was still there along with the vibrations between 1500-2000 rpm. I again experimented with adding weights and while adding a weight next to the oem one helped it - it was never perfect and I wasn't really happy with it. Especially having another car at home that sounded and felt much better. So I brought it back to dealer thinking they'll say they cannot do anything. But to my surprise the tech heard the noise. Diagnosed it as a rattling/bad separator inside the y-pipe (it's a small Y pipe in front of the mid-pipe. Apparently it's not just a simple pipe but it has some sort of separator inside) and replaced it.
It made a noticeable difference although still not perfect.

Last edited by Stans; 07-16-24 at 06:03 AM.
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Old Yesterday, 07:37 AM
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Originally Posted by Stans
This might help someone so here we go:
One of my RX's (I own 2 of them) had this pretty awful droning noise. I tried playing with weights adding them to different spots on the pipe which did not make a huge difference. So I decided to take it to Lexus. As expected they installed the updated midpipe with weight attached which reduced the drone a lot to my surprise... I lived with it for a few months and after driving the car in different conditions I realized that the drone was reduced but it was still there along with the vibrations between 1500-2000 rpm. I again experimented with adding weights and while adding a weight next to the oem one helped it - it was never perfect and I wasn't really happy with it. Especially having another car at home that sounded and felt much better. So I brought it back to dealer thinking they'll say they cannot do anything. But to my surprise the tech heard the noise. Diagnosed it as a rattling/bad separator inside the y-pipe (it's a small Y pipe in front of the mid-pipe. Apparently it's not just a simple pipe but it has some sort of separator inside) and replaced it.
It made a noticeable difference although still not perfect.
This is very promising! What year are your cars?

I scheduled my 2022 RX350 to get this done on Monday. I'll report back with results.
Old Yesterday, 07:50 AM
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Originally Posted by starcube
This is very promising! What year are your cars?

I scheduled my 2022 RX350 to get this done on Monday. I'll report back with results.
2020 and 2021
Old Yesterday, 07:57 AM
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Originally Posted by Stans
2020 and 2021
And which one was droning?
Old Yesterday, 08:15 AM
  #2181  
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Originally Posted by starcube
And which one was droning?
21 was droning. 2020 was a bit louder in the 1500rpm but it was easily cured by me adding 1 damper on a clamp in the stock location.

So after driving it for a few days it feels better. It used to drone horribly at 1800rpm. Exactly 67mph when driving on the highway in top gear. It is fully gone now. Silky smooth and no drone at this rpm. The only thing remains is a 1500rpm booming noise/vibration that seems to be unavoidable to a certain degree on these cars. It is still a bit louder than my other car in this rpm range but nowhere near as bad as it was previously. Also it cannot be heard at all when accelerating normally. Only when it stays in this rpm under load or a very slow acceleration.
One thing that I still want to try is measure the exhaust flange clearances and compare that between the 2 cars. It was reinstalled twice at this point and I would like to make sure that it's the same..
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Old Yesterday, 01:09 PM
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Originally Posted by Stans
This might help someone so here we go:
One of my RX's (I own 2 of them) had this pretty awful droning noise. I tried playing with weights adding them to different spots on the pipe which did not make a huge difference. So I decided to take it to Lexus. As expected they installed the updated midpipe with weight attached which reduced the drone a lot to my surprise... I lived with it for a few months and after driving the car in different conditions I realized that the drone was reduced but it was still there along with the vibrations between 1500-2000 rpm. I again experimented with adding weights and while adding a weight next to the oem one helped it - it was never perfect and I wasn't really happy with it. Especially having another car at home that sounded and felt much better. So I brought it back to dealer thinking they'll say they cannot do anything. But to my surprise the tech heard the noise. Diagnosed it as a rattling/bad separator inside the y-pipe (it's a small Y pipe in front of the mid-pipe. Apparently it's not just a simple pipe but it has some sort of separator inside) and replaced it.
It made a noticeable difference although still not perfect.
Does that mean somethiing was broken inside? If yes, we can confirm that with a rubber mallet.

I dont think that is the case for the majority of the owners here. This is the characteristic of the vehicle is the flaw. What we are only trying to do is masking the problem.

I believe the root cause is due to the TNGA platform has changed as explained by The Car Care Nut. The engine mounts are mounted in the not ideal locations. Where the engine vibrations are not absorbed by the engine mounts well and gets transfered throughout the the exhaust system. Then it is felt in the cabin as the exhaust system is right below it.

Last edited by GS4_Fiend; Yesterday at 01:13 PM.
Old Yesterday, 05:11 PM
  #2183  
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Originally Posted by GS4_Fiend
Does that mean somethiing was broken inside? If yes, we can confirm that with a rubber mallet.

I dont think that is the case for the majority of the owners here. This is the characteristic of the vehicle is the flaw. What we are only trying to do is masking the problem.

I believe the root cause is due to the TNGA platform has changed as explained by The Car Care Nut. The engine mounts are mounted in the not ideal locations. Where the engine vibrations are not absorbed by the engine mounts well and gets transfered throughout the the exhaust system. Then it is felt in the cabin as the exhaust system is right below it.
Looks like the separator inside the pipe wasn't in best shape. And i never said it was a universal fix. My opinion is that vibrations and noise are really coming from exhaust and not the engine vibrations. And I think it might be in part related to the flange connector and its tightness. I actually tried loosening the bolts a little at some point and that changed both vibrations and drone. But as you said my car had additional issue and so that test was pointless.
Old Yesterday, 09:34 PM
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Originally Posted by Stans
Looks like the separator inside the pipe wasn't in best shape. And i never said it was a universal fix. My opinion is that vibrations and noise are really coming from exhaust and not the engine vibrations. And I think it might be in part related to the flange connector and its tightness. I actually tried loosening the bolts a little at some point and that changed both vibrations and drone. But as you said my car had additional issue and so that test was pointless.
You mean this section?


Old Today, 05:00 AM
  #2185  
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Originally Posted by GSFRX350
You mean this section?

yes and these two bolts with springs
Old Today, 05:51 AM
  #2186  
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Originally Posted by Stans
yes and these two bolts with springs
I absolutely agree. Since soon after this thread started I've said the same thing, mainly because of all the stories about how some are affected and others aren't, some had that TSB done that added the damper but still some had success while others didn't. THAT section can be tightened to different degrees and that could explain why different vehicles are different.

I could imagine when you take the car on for the TSB they probably put the most junior person on it, a simple part replacement and the inexperienced mechanic could well not tighten correctly.

Also, in Australia we only have Japan built vehicles and there is no talk here about these vibration issues, there's no TSB issued for it. I never really felt anything until I read about it on here, that's when I took more notice and thought, yes, there is a minor vibration at certain revs, not bad though. Maybe it's as simple as tightening that flange correctly to remove the vibration.
Old Today, 06:20 AM
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Originally Posted by GSFRX350
I absolutely agree. Since soon after this thread started I've said the same thing, mainly because of all the stories about how some are affected and others aren't, some had that TSB done that added the damper but still some had success while others didn't. THAT section can be tightened to different degrees and that could explain why different vehicles are different.

I could imagine when you take the car on for the TSB they probably put the most junior person on it, a simple part replacement and the inexperienced mechanic could well not tighten correctly.

Also, in Australia we only have Japan built vehicles and there is no talk here about these vibration issues, there's no TSB issued for it. I never really felt anything until I read about it on here, that's when I took more notice and thought, yes, there is a minor vibration at certain revs, not bad though. Maybe it's as simple as tightening that flange correctly to remove the vibration.
I'm not even sure it's a matter of simply torqueing the bolts. I think it's more of having the right and even clearance on all sides which will result in the same torque on the bolts only if both bolts and nuts are clean, spin freely, springs have no differences and the whole part including the gasket is totally straight and even.


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