RX450H vibrates when accelerates

vmehta · April 2, 2021

Hello,

I have RX450H 2017 and 29K on it. Recently car has started to vibrate when trying to accelerate from slow movement. Till its on Battery I don't feel vibration but the moment it comes on engine , I feel vibration.

Vibration is like as if trying to accelerate engine on slow motion when on high gear.

Car dashboard or diagnosis doesn't give any problem

Any idea what could be the problem.

ColinBarber · April 2, 2021

no real solution as yet but does this thread describe your symptoms?

olliesgrandad · April 2, 2021

Have you thought about tyre wear. My series 3 had Dunlop tyres which when worn gave a vibration like a worn wheel bearing. Ive just changed tyres on my 2017 Premier from Bridgestones to Yokahoma and the difference is amazing.

stringbender · April 3, 2021

11 hours ago, vmehta said:

Hello,

I have RX450H 2017 and 29K on it. Recently car has started to vibrate when trying to accelerate from slow movement. Till its on battery I don't feel vibration but the moment it comes on engine , I feel vibration.

Vibration is like as if trying to accelerate engine on slow motion when on high gear.

If the vibration has only just started then Les may be right about the tyres. Worth thinking about. My first 4RX was a 2017 Premier but I got fed up with the vibration at about 1,100 rpm and eventually decided to sell it. None of the 4RX I've driven were as silky smooth as my 2005 SEL and neither is the one I'm driving now. In the thread that Colin showed a picture of the original poster even fitted dampers but that didn't work either. I've bought an endoscope to see if I can see what's going on whilst I drive so how desperate is that ! Do please report back on how you're getting on.

Alan

ColinBarber · April 3, 2021

It is disappointing that these vibrations occur in the drivetrain, seemingly because of very low rpm of the ICE in certain scenarios. The IS300h has this issue and Lexus developed a damper that partially solved the problem, along with the ECU update to stop the engine running at the resonance rpm as much. Given these issues were known as the series IV RX was being developed you would think more care would have been taken.

https://www.lexusownersclub.co.uk/forum/topic/98541-is300h-permanent-drivetrain-vibrations-1300rpms/

However given that the OP's issue has just started, in this case it seems to be something worn, rather than a design/build issue. Possibly tyres, although I'd expect the issue to also be apparent when on electric power, not just when the ICE is running. Engine mounts are a possibility but I wouldn't expect any issue with those at only 29k miles.

Spacewagon52 · April 3, 2021

I have noticed a vibration through the seat on my 400h. Have you tried (when it is safe to do so) slipping the gear into neutral? Is the vibration still there?

Tyres are often a cause when they wear. My tyres are due to be changed as they are over 5 years old and showing signs of grazing on the rears.

Years ago I had a similiar problem with a car and changed all four tyres. They did not need changing as they had plenty of tread but was recommended to try it.

Unfortunately it did not solve the problem. If your tyres are fairly well worn or have been on the car sometime, I would change them. That is what I am going to do with mine. Will update if it cures the problem.

Barry14UK · April 3, 2021

As regards car tyres, although the Dunlops that were on my car as purchased still had a lot of tread, this was stepped on the rears. It gave a wine and slight resonance like a worn bearing but not what I would say amounted to vibration, although this can be subjective and may have got worse with more wear. I can truly say that the Cross Climates stopped this completely among other benefits. However, I don't think the Lexus V6 engine is as smooth as my BMW straight 6, especially at low revs. Maybe this of this at least is due to working with the pretty unique type of transmission. My old 2.5 Camry V6 with more conventional autobox was very smooth.

ColinBarber · April 3, 2021

1 hour ago, Barry14UK said:

However, I don't think the Lexus V6 engine is as smooth as my BMW straight 6, especially at low revs. Maybe this of this at least is due to working with the pretty unique type of transmission. My old 2.5 Camry V6 with more conventional autobox was very smooth.

That's a little unfair, inline 6 engines are super smooth, more so than V6s. The modern V6s with very high compression ratios aren't as smooth as older V6s.

I don't think it is the engine smoothness at fault here though - there is possibly resonance vibration elsewhere causing the issue (triggered by the engine).

C Mclean · April 4, 2021

Still got the vibration/resonance at 1150 to 1200 RPM, added a couple of the weighted dampers to the exhaust but it just altered the RPM when the vibration occurred. Took one of them off and it seemed to reduce the vibration very slightly so I reckon that’s about as good as I’m going to get it.

stringbender · April 4, 2021

I disliked the vibration on my first 4RX ( GU17LNP ) that I sold it after a year. Whilst they were trying to fix it I tried several others but only one was as smooth as my old 2005 RX SEL. None of them were as bad as GU17 and I made the decision to go for a new Takumi and keep my fingers crossed. My latest is nowhere near as bad as GU17 but I know exactly when the ICE is doing 1,100 rpm or thereabouts. Everything else about the car is amazing but this one is on a PCP and will go after the 3 years. It may be the end of my Lexus days which will be very sad.

Thanks Colin. I read the whole of that thread on vibration of the IS going back to 2015. There you read about vibration in a 50 mph zone going slightly uphill which is exactly what I got going up from Avonmouth to Cribb's on the M5 and I told Lexus Bristol about so often. I was written off as a crank and I do admit that I'm very fussy but being joggled about is something I hate.

I'm no further on but this one fact is VERY clear now. For the first 2 or 3 minutes when the car is cold it is perfect. Then, as I guess something warms up, you feel the engine begin to pass its vibrations into the cabin.

I've noticed something that looks like it can be adjusted and is then machine bolted to the top mount on the drivers side of the engine. I'd include a photo but don't know how to ! Wonder what that's for ?

My experiments with the camera scope haven't achieved anything but I'll never stop trying. From Colin's thread it seems Lexus are well aware there is some kind of problem and I guess that's why they bolted an 800+gram weight onto the exhaust pipe around the cat. If you remove that then there is no change at all so it's a total waste of time.

Alan

C Mclean · April 6, 2021

O.K. so I’ve put on my Kevlar suit before mentioning this but the Lexus is due it’s MOT this month and I’ve had a look at the UX300e. Not really impressed by the space in the back, Battery range or price, now considering the MB EQA. Quickly ducks below the parapet for mentioning MB, would have been a bigger sin if it was BMW.

Spacewagon52 · April 6, 2021

30 minutes ago, C Mclean said:

O.K. so I’ve put on my Kevlar suit before mentioning this but the Lexus is due it’s MOT this month and I’ve had a look at the UX300e. Not really impressed by the space in the back, battery range or price, now considering the MB EQA. Quickly ducks below the parapet for mentioning MB, would have been a bigger sin if it was BMW.

Bite the bullet, get it MOT'd and KEEP it!

Barry14UK · April 6, 2021

There is a lot of technology in the EQA, fine if all works well for the long term. https://www.mercedes-benz.co.uk/passengercars/mercedes-benz-cars/models/eqa/explore/design.module.html?csref=mc_sem_cn-GBR_RG_MBC_Product_EQC_Exact_ci-Google_si-g_pi-kwd-545667128293_cri-496363224233_ai-ppc1907080136&kpid=go_cmp-11912134474_adg-119250222607_ad-496363224233_kwd-545667128293_dev-c_ext-#

A big determining factor in considering an electric vehicle is the type of journeys you make and at what speed. On genuine road tests have invariably shown that electric cars fall short of the distance advertised by manufacturers which is made worse if the car is used for long distances at 70mph. Also with the passing of time the traction Battery decreases its ability to provide propulsion for as long a distance. https://arstechnica.com/cars/2020/08/teslas-model-3-beats-competitors-in-70mph-range-test/ . Advances with Battery technology providing greater distances on a charge and faster chargers will clearly make BEV more attractive to drivers but is it a good time to buy yet? Maybe worth staying with Lexus Hybrid for awhile.

stringbender · April 7, 2021

22 hours ago, C Mclean said:

O.K. I’ve had a look at the UX300e. Not really impressed by the space in the back, battery range or price, now considering the MB EQA.

On Sunday I was taken out in my son in laws new all electric Mercedes which I think was an EQC to replace his GLC.

So quiet, so SMOOOTH, I was blown away by it. Zero vibration at any speed. Guess I'll have to dream on and on.

royoftherovers · April 7, 2021

44 minutes ago, stringbender said:

On Sunday I was taken out in my son in laws new all electric Mercedes which I think was an EQC to replace his GLC.

So quiet, so SMOOOTH, I was blown away by it. Zero vibration at any speed. Guess I'll have to dream on and on.

Thanks for the information Alan. It does sound, if you`ll forgive the pun, like a nice car to have.

Please report back on the attitude of the M.B. Dealership if and when he experiences matters which need to be referred to it.

C Mclean · April 7, 2021

Sad to say but I should be able to downsize a bit later this year when I don’t have to carry wife’s mobility stuff. In general I’d just be pottering around locally with the odd 250 mile return trip a couple of times a year. Got an ace up my sleeve regarding the dealership standards, daughter’s husband is an after sales director with an MB dealership group. Everything’s a just maybe at the moment and as time goes on I’ll see what suits me best.