2016 RX 350 Excessive noise and vibration
#1877
I believe you were the one questioning me. So moving this along, what is your dealer doing with your case? I don’t doubt there is something that you & your dealer heard. Is it the dreaded droning issue? I’m not sure. How about an olive branch? Make some recordings so we all can hear what you hear. There’s a decent chance someone on here has heard what you are hearing. Did you buy your 450h new? If not, do you have the service history. Has your car ever been wrecked. I ask, because I had a wreck in another car & after it was repaired, I had creaking & groaning noises that I never had before. I’m throwing out some off the wall possibilities, since your issues is a rare one. Fair enough?
It is dreaded droning.
As I showed in the picture above, adding the weight reduced it quite substantially.
Now that I have weight there, and it's reduced, it would be hard to record it, with road noise. When I have a chance, I will try but it may take a while before I get to it (taking it off and recoding original full drone).
I will post it when I have it
P.S. And even if I have it, I am interested in any ideas to fix, not reaffirmation that it's drone. I drove loaner 350s too and I heard it as well. there is youtube video too of its sound, it's hard to mistake it
Last edited by vmoldovan; 12-21-20 at 06:16 PM. Reason: P.S.
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gadgetman1 (12-22-20)
#1878
Well, it certainly sounds like you did your homework & know something about these vehicles. There has to be something that’s different on your model - maybe something was changed out for warranty or other service work. Something is clearly different about your 450h, vs. mine & others that don’t get any drone. Have you ever had the transmission serviced? This is just a long shot, but consider getting a sample of your transmission fluid sent to Blackstone Labs for analysis. Perhaps there is something in your transmission that’s causing the drone. Sometimes mine will shift up to high gear (not sure what that really is on a CVT) at lower speeds & it causes a bit of a low frequency vibration/noise, but it’s really not noticeable, unless you are listening for it. I’m very sensitive to that sort of stuff, but mine is so subtle, that it doesn’t bother me. On my Camaro SS, if I shift up to 6th gear (manual transmission) before 50 mph, it really makes some annoying noise & vibration & let’s you know it doesn’t line that gear.
#1879
Some scientific evidence of drone in RX 450h
Well, it certainly sounds like you did your homework & know something about these vehicles. There has to be something that’s different on your model - maybe something was changed out for warranty or other service work. Something is clearly different about your 450h, vs. mine & others that don’t get any drone. Have you ever had the transmission serviced? This is just a long shot, but consider getting a sample of your transmission fluid sent to Blackstone Labs for analysis. Perhaps there is something in your transmission that’s causing the drone. Sometimes mine will shift up to high gear (not sure what that really is on a CVT) at lower speeds & it causes a bit of a low frequency vibration/noise, but it’s really not noticeable, unless you are listening for it. I’m very sensitive to that sort of stuff, but mine is so subtle, that it doesn’t bother me. On my Camaro SS, if I shift up to 6th gear (manual transmission) before 50 mph, it really makes some annoying noise & vibration & let’s you know it doesn’t line that gear.
Let's bring some science into this.
RX 450h has V6. V6 produces three exhaust pulses per revolution (V8 > 4 pulses and 4-cyl > 2). My sports mode tachometer shows drone at approx. 1700 to 1800 RPM. let's pick 1750 RPM. 1750 R(evolutions) P(er) M(inute) / 60 sec => 29.1666 times a second * 3 pulses per second = 87.5 Hz frequency. Thus, this is a natural exhaust frequency at 1750 RPM of V6 engine.
I used Sound Spectrum Analyzer app, to split sound low frequencies and here is what it showed, see below.
It confirmed beyond any doubt that frequency of this spike matches exhaust frequency at that RPM and thus by definition is what is called "exhaust drone". that is how I understand it. Anyone is welcome to correct me here.
I still have additional Toyota weight on my exhaust pipe so drone is mitigated with it. It seemed like 50% originally, sometimes it seems somewhat less but nevertheless mitigated.
Also it's been really cold (-18 C, 0 F) where I live and that was the temperature when I drove to make this capture, and according to my personal observations it appears that cold tones down this drone firther.
I need to buy this app to save audio recorded. I have fancy sound recorder and I wil try to record sound inside a cabin when it warms up a bit and then use different spectrum analyzer on that audio file.
So these are my additional facts about my drone.
Helmholtz tube (or J tube) at 1/4 wave length, 38" in length would likely kill this drone. Math I used is: Length= 1100 / Drone freq / 4 * 12. That is one potential fix.
But before that, I will gather more data and will take it to Lexus again. Exhaust is under 96 months or 80,000 miles emmision warranty. I don't think I should be doing custom solutions to my vehicle, not yet.
P.S. The goal of good exhaust design is to mitigate these frequencies but it appears in my case Lexus exhaust fails to mitigate it sufficiently and it reaches cabin and my ears. Or something is defective about my exhaust and at 57K KM or 35K miles it should not happen.
Last edited by vmoldovan; 12-29-20 at 07:12 AM. Reason: added math for J pipe
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bamalam (12-28-20),
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#1880
That’s some great research you’ve done! However, it still doesn’t answer the question as to why YOUR vehicle is so much worse than say mine or anyone else? What’s different? I will say that on a test drive of a 350 & on a few of the 350 loaners I’ve had, I got a pronounced, sharp, rattle from the exhaust at certain RPMs. It was loud, just like the YouTube video. That’s the sole reason I didn’t buy the 350. My 450h has never done that.
I suggested this before to someone, about installing exhaust wrap on your pipe. That should quiet it down some & doesn’t involve removing anything or welding. It’s worth a try before doing an exhaust modification. If I were in your shoes, either the exhaust would go or the whole car. This is too expensive of an automobile to play these kind games & put up with stupid automakers & dealers.
I suggested this before to someone, about installing exhaust wrap on your pipe. That should quiet it down some & doesn’t involve removing anything or welding. It’s worth a try before doing an exhaust modification. If I were in your shoes, either the exhaust would go or the whole car. This is too expensive of an automobile to play these kind games & put up with stupid automakers & dealers.
#1881
I have been meaning on purchasing a set of the Steelman Wireless ChassisEAR just so I can diagnose exactly which area is causing the most drone. Been so busy with life that I have not bothered yet, but seeing @vmoldovan 's post above is giving me an itch to get it.
Here is a clip at the 13min 20sec mark to give a demonstration on what these are.
Here is a clip at the 13min 20sec mark to give a demonstration on what these are.
The following users liked this post:
gadgetman1 (12-28-20)
#1882
#1883
I have been meaning on purchasing a set of the Steelman Wireless ChassisEAR just so I can diagnose exactly which area is causing the most drone. Been so busy with life that I have not bothered yet, but seeing @vmoldovan 's post above is giving me an itch to get it.
Here is a clip at the 13min 20sec mark to give a demonstration on what these are.
Here is a clip at the 13min 20sec mark to give a demonstration on what these are.
#1884
That is an awesome piece of equipment!! Clearly, it doesn’t appear the Lexus techs are using anything as sophisticated or useful as this! I’m really eager to find out what is making these horrible drone noises & why some have it & others don’t. I’m very impressed at both of your work on this. If you want something done right, you have to do it yourself.
Last edited by rxtimes2; 12-29-20 at 04:29 AM.
#1885
I have recently purchased a 2016 Lexus RX350. I love both the exterior and interior design along with the electronic driver aids. However, I am extremely disappointed with the excessive noise and vibration I have experienced from a standing stop.
This is my first purchase of a Lexus product and expected a much higher level of refinement.
Has anyone else had a similar experience?
Jim
This is my first purchase of a Lexus product and expected a much higher level of refinement.
Has anyone else had a similar experience?
Jim
#1886
2017 RX350. Muffler TSB, Hesitation TSB already applied.
Vibration goes away as you you give it some gas and RPMs rise.
Last edited by NCRX350; 12-30-20 at 11:55 AM.
#1887
Engine Noise minor vibration on steering wheel.
Guys,
I have an RX350L 2018. The engine noise is quite loud and there is major vibration during idling in the drive gear. Iding in Park isn't bad but you definitely feel the vibration when I am idling in gear.
I brought the Lexus dealer and have them checked and they can't find anything wrong with it and they said it is normal for that version of RX350L. I think they BSing me as it is not a luxury car feel. It should be quiet during idle.
is your quiet? can you hear the engine noise while idling?
I have an RX350L 2018. The engine noise is quite loud and there is major vibration during idling in the drive gear. Iding in Park isn't bad but you definitely feel the vibration when I am idling in gear.
I brought the Lexus dealer and have them checked and they can't find anything wrong with it and they said it is normal for that version of RX350L. I think they BSing me as it is not a luxury car feel. It should be quiet during idle.
is your quiet? can you hear the engine noise while idling?
#1888
Unfortunately with the 4th-gen RX350s, the louder-than-usual engine noise and vibration is pretty common as the engine was changed to include both port and direct injection.
I have both issues, and you may notice the vibration gets worse with the A/C turned on since that adds extra load to the engine. Some of the earlier 4th-gen RX350s had issues with the vaccum pump where it would make a loud knocking sound: https://www.clublexus.com/forums/rx-...e-noise-2.html
I have both issues, and you may notice the vibration gets worse with the A/C turned on since that adds extra load to the engine. Some of the earlier 4th-gen RX350s had issues with the vaccum pump where it would make a loud knocking sound: https://www.clublexus.com/forums/rx-...e-noise-2.html
#1889
OMG, so it is normal or only certain vehicle? can it be fixed? it is Lexus we are talking about, only older cars with little maintenance make a noise like that. my car is barely 9k on it. what a shame to the Lexus brand. I am opening a case with Lexus, maybe they can do something about it.
#1890
I lost my 2015 in an accident and got my 2018 about 3 weeks later, so I had the opportunity to compare them fairly directly. I noticed immediately that the 2018 was louder, when standing beside the front end of the car. The "knocking" noise of the fuel injectors was much more noticeable. Once inside, I only notice the engine noise when accelerating. There's a resonator on the F-Sport that I could swap out for the standard and reduce that a bit, but it doesn't bother me. But they increased the horsepower 45 hp from Gen 3 to Gen 4, so it's not unreasonable to expect a louder motor. As far as vibration, no, I feel no significant vibration in the steering wheel, or elsewhere, and mine has zero rattles, at 32K miles.
Last edited by dibl; 01-08-21 at 02:03 PM.