Noisier than I expected. Is this normal?

Rhub · December 28, 2018

I've just bought a 57 plate RX 400h with 112,000 miles and an impeccable service history of ten main dealer stamps. I love the drive but am surprised and disappointed about how much road noise there seems to be. There is a constant 'whooshing' noise as soon as you go faster than 20 miles an hour. The tyres on the front are brand new Falken Azenis and there are two good Bridgestone Potenzas on the rear. I'm not sure whether the noise is the tyres but it seems a good place to start.

I can't detect anything wrong with the door or window seals but it definitely sounds like more noise is coming into the cabin than you would expect.The nearest analogy I can provide is that it sounds a bit like the noise you get in a fast train because of the air pressure.

Am I expecting too much from the car in terms of its quietness? I would be very pleased if some more experienced drivers of these cars could let me know what is normal.

Herbie · December 28, 2018

Tyres play a massive part in road noise. Have a look on any tyre website to see what their sound rating is.

olliesgrandad · December 28, 2018

You need 4 matching tyres on these cars. Certain brands on the rear wear in a stepped pattern and that is when a rumble like a wheel bearing starts. I've had this with my RX450h and changing tyres instantly cured the issue.

Hadrian · December 28, 2018

I noticed the noise on my IS300h. I changed to "low noise" tyres, but it didn't make a great deal of difference.

ColinBarber · December 28, 2018

It doesn't sound normal. Either tyres, poor air seal around door/window or something like a wheel bearing. Difficult to determine without hearing it but my old 400h was very quite at anything up to 60 mph.

welland · December 28, 2018

Rhub,

Is the sound the same on all road surfaces? Does it vary with your speed? Have you tried lowering and raising all your windows, and the sunroof a little? Does it make any difference?

Hadrian · December 29, 2018

10 hours ago, Hadrian said:

I noticed the noise on my IS300h. I changed to "low noise" tyres, but it didn't make a great deal of difference.

Just to add, I may notice it more as I have to wear hearing aids. Which tend to amplify some frequencies more than others.

Rhub · December 29, 2018

Thank you everyone for your suggestions. I tried lowering the windows a little and using the sunroof (thank you Welland) but there is no change in the noise. Different road surfaces alter the intensity of the noise but even on a really smooth surface, there is still a constant whooshing. This afternoon I used masking tape all round the driver's door to see if it would improve the seal but it didn't make any difference at all. I think it must simply be the noise from the tyres and perhaps it is the fact that I have different brands on the front and back as Olliesgrandad says that is causing the problem. The Bridgestones are rated E/E/71 dbs and the Falkens are C/A/70 dbs. I may have to bite the bullet and buy a set of four matching tyres but what do you suggest from your experience? I can't find any tyres that are quieter than 67 dbs (Goodyear Efficient Grip). A couple of Michelins are 69 dbs (Cross Climate and Primacy 3). Your views would be very welcome.

jumpingjehovahs · December 29, 2018

I was thinking about this post as I was out in mine earlier. I find shutting the sunroof cover/blind makes a huge difference (in Lexus noise terms) to the amount of noise in the cabin.

I don’t have the panoramic roof, just a standard sunroof, but do try to do high speed trips with the blind shut as it’s a little more peaceful.

Sent from my Iphone using Tapatalk

Herbie · December 29, 2018

When I had my RX300 I had Avon ZX7 all round and there was certainly no excessive noise from them - great tyres and highly recommended.

On my current RX450h I've got Goodyear Vector 4Seasons Gen 2 all round and they are excellent. Very quiet, great grip and very highly recommended.

Rhub · December 29, 2018

Thanks Herbie, that's really useful to know. I've just looked them up and found this review in Auto Express. Interestingly, they came first for lack of cabin noise and they are well priced compared to the Michelins.

https://www.autoexpress.co.uk/accessories-tyres/92869/goodyear-vector-4seasons-gen-2

olliesgrandad · December 29, 2018

2 hours ago, Rhub said:

Thank you everyone for your suggestions. I tried lowering the windows a little and using the sunroof (thank you Welland) but there is no change in the noise. Different road surfaces alter the intensity of the noise but even on a really smooth surface, there is still a constant whooshing. This afternoon I used masking tape all round the driver's door to see if it would improve the seal but it didn't make any difference at all. I think it must simply be the noise from the tyres and perhaps it is the fact that I have different brands on the front and back as Olliesgrandad says that is causing the problem. The Bridgestones are rated E/E/71 dbs and the Falkens are C/A/70 dbs. I may have to bite the bullet and buy a set of four matching tyres but what do you suggest from your experience? I can't find any tyres that are quieter than 67 dbs (Goodyear Efficient Grip). A couple of Michelins are 69 dbs (Cross Climate and Primacy 3). Your views would be very welcome.

Michelin Cross Climates. I drive 500 miles a week and they are fantastically quiet and very grippy. They are allegextfo last 11,000 miles more than the competition

ColinBarber · December 29, 2018

2 hours ago, Rhub said:

The Bridgestones are rated E/E/71 dbs and the Falkens are C/A/70 dbs. I may have to bite the bullet and buy a set of four matching tyres but what do you suggest from your experience? I can't find any tyres that are quieter than 67 dbs (Goodyear Efficient Grip). A couple of Michelins are 69 dbs (Cross Climate and Primacy 3).

Don't get too hung up on the noise rating of tyres. It is based on a smooth road surface that you don't find in this country and is measured by the sound heard at the roadside 1m away - tyre manufactures can actually design their tyres to do well in this test by directing the sound away from the kerb and into the cabin - which means a better rated tyre can actually be noisier to the driver than a poorly rated tyre.

welland · December 29, 2018

3 hours ago, ColinBarber said:

Don't get too hung up on the noise rating of tyres. It is based on a smooth road surface that you don't find in this country and is measured by the sound heard at the roadside 1m away - tyre manufactures can actually design their tyres to do well in this test by directing the sound away from the kerb and into the cabin - which means a better rated tyre can actually be noisier to the driver than a poorly rated tyre.

That's interesting, I had always mistakenly thought that the noise rating was a measure of noise inside the car, not outside.

welland · December 29, 2018

On 12/28/2018 at 8:54 PM, olliesgrandad said:

You need 4 matching tyres on these cars. Certain brands on the rear wear in a stepped pattern and that is when a rumble like a wheel bearing starts. I've had this with my RX450h and changing tyres instantly cured the issue.

I'm not really sure I believe that it's necessary to have four matching tyres. If a certain brand / model of tyre is prone to poor lifetime, noise or grip, how can it be made worse by choice of tyres fitted on the other wheels? This would imply that four matching "poor" tyres is better than a mix of the same poor tyres with other "better" tyres.

welland · December 29, 2018

6 hours ago, Rhub said:

Thank you everyone for your suggestions. I tried lowering the windows a little and using the sunroof (thank you Welland) but there is no change in the noise. Different road surfaces alter the intensity of the noise but even on a really smooth surface, there is still a constant whooshing. This afternoon I used masking tape all round the driver's door to see if it would improve the seal but it didn't make any difference at all. I think it must simply be the noise from the tyres and perhaps it is the fact that I have different brands on the front and back as Olliesgrandad says that is causing the problem. The Bridgestones are rated E/E/71 dbs and the Falkens are C/A/70 dbs. I may have to bite the bullet and buy a set of four matching tyres but what do you suggest from your experience? I can't find any tyres that are quieter than 67 dbs (Goodyear Efficient Grip). A couple of Michelins are 69 dbs (Cross Climate and Primacy 3). Your views would be very welcome.

Some other ideas:

Is the noise the same throughout the cabin, or worse in any particular place?

If it sounds like wind noise, is there any damage in the door seals? Or could any of the doors be not shut properly? You might need somebody else to drive while you move yourself around the cabin to check this properly.

Have you checked the tracking? If this is out of tolerance, the tyres could be scrubbing, and thus causing too much noise?

Have you asked a mechanic to have a listen - it could be a wheel bearing. Earlier this year I had an intermittent noise on mine. At first it was quiet and even my mechanic didn't identify the wheel bearing. But the noise was worse when turning corners. I checked the tracking and found it out of tolerance. When this was adjusted, the noise problem was improved, but over time, the bearing got worse until it became obvious that was the cause of noise?

Have you checked the brakes- a rough disc with binding brake could cause noise.

Rhub · December 30, 2018

Thank you everyone for your help.

The tracking is fine as it was checked at my request when the car was MOTed before I bought it. I had asked for this because when I road tested the car, it had tended to move to the left when you took your hands off the steering wheel. I accepted the dealer's view that it wasn't actually 'pulling to the left' but was simply responding to the camber of the road, which, I was told, I would have to expect with a heavy car with big tyres. The MOT garage reported that the tracking was spot on.

I am pretty sure it is not a wheel bearing. I have been out with my brother-in-law who knows about such things and he doesn't think that this would explain the noise. I am, however, aware from other sources that it can be very hard to detect this issue in its early days. I will keep it on the list of possible solutions. Also, I don't think it is a brake noise but will keep this in mind.

I agree with jumpingjehovahs that the sun roof is quite a lot noisier with the cover pulled back but this isn't the source of my problem.

I think I am going to put a set of four new tyres on the car (probably Michelins or Goodyears) and take it from there. I can get the wheel bearings checked at the same time. I will let you know how I get on.

olliesgrandad · December 30, 2018

9 hours ago, welland said:

I'm not really sure I believe that it's necessary to have four matching tyres. If a certain brand / model of tyre is prone to poor lifetime, noise or grip, how can it be made worse by choice of tyres fitted on the other wheels? This would imply that four matching "poor" tyres is better than a mix of the same poor tyres with other "better" tyres.

The characteristics of the car will be affected by the difference in grip and water clearance behaviour between different tyres especially on such a powerful car. Even a different model of the same tyre can make a big difference at high speed. When I was in the police all cars were fitted with Goodyear tyres. One of our cars had a pair replaced with an upgraded model tyre and no one noticed until it took a big 'Off' into the Forest of Dean on an emergency call..

Hence I am very wary about mixing tyres

Rhub · December 30, 2018

I don't want you to think that I am an obsessive nerd about this but just out of interest I downloaded a free decibel measuring app for my phone and used it to compare sound levels in the Lexus with those in two other cars I have access to. I did the same course along a stretch of motorway at 70 miles an hour with the phone in the same position fixed to the dashboard. I know that this isn't scientifically valid but for what it's worth here are the results.

There is virtually no difference between the three cars. The average level was 74.7 dB in the Lexus; 75.8 in a Subaru Legacy estate; and 75 .7 in a Megane coupe. So the Lexus is very slightly quieter. However, I think this explains my frustration since the Subaru in particular is a noisy engine with a slightly sporty exhaust. I was expecting the Lexus to be much quieter than that car. There is no doubting the lovely quietness of Lexus's engine but perhaps this is where my problem comes from. The quietness of the engine makes the 'normal' road level noise seem all that more intrusive.

welland · December 30, 2018

13 hours ago, olliesgrandad said:

The characteristics of the car will be affected by the difference in grip and water clearance behaviour between different tyres especially on such a powerful car. Even a different model of the same tyre can make a big difference at high speed. When I was in the police all cars were fitted with Goodyear tyres. One of our cars had a pair replaced with an upgraded model tyre and no one noticed until it took a big 'Off' into the Forest of Dean on an emergency call..

Hence I am very wary about mixing tyres

Ok, I see what you mean. I fully understand how mixing tyres with different grip performance is a potential disaster when driving at the limits of adhesion. For example, following a puncture, if one tyre is replaced, there might be better cornering grip in one direction than the other. But for most drivers, this would be ok, if the remaining tyre on that axle does not have wildly different performance to the new one.

In general, though, I feel it is fine to replace tyres in pairs across an axle. As long as grip is similar on both ends of an axle, grip performance shouldn't be unpredictable, nor cause problems for most drivers. Normally, we all try to drive well within the combined limits of our vehicles and our own skill (don't we?), so that we have something in reserve when unexpected circumstances occur. But those who drive closer to the limits than most (eg police, enthusiastic drivers, etc....) should pay more attention to their tyres.

I mistakenly thought that you were linking mixed tyres with stepped wear pattern and or road excessive road noise.

Herbie · December 30, 2018

Rightly or wrongly, I tend to think that someone who has all four tyres matching (as long as they are a well-known and respected brand of course) is more likely to have looked after the car more than someone who has mixed tyres.

Rhub · January 12, 2019

I said I would let you know how I got on with tackling the noise issue I was struggling with. Well, here goes.

I went out with a mechanic from my local trusted garage and he could hear lots of road noise but didn't think there was anything else to worry about. We had the car up on a ramp as well and he confirmed that the wheel bearings were absolutely fine and that the car was in exceptionally good condition for its age. I therefore decided to bite the bullet on buying new tyres and went for four Michelin Cross Climate which several people on various forums, including this one, recommenced as quiet tyres. I am very pleased with them and they are definitely quieter than what I had on before BUT there was still a whooshing noise which I didn't think should be there.

I couldn't identify where the noise was coming from other than it was near the side window. I wondered if I could stuff something in the widow seal to see if that made a difference and found some little polystyrene packaging chips which fitted snugly in the channel along the bottom of the window. I was convinced that it made the car quieter bit was obviously entirely impractical! My next move was to buy some black tubing off eBay which I cut to the right length and fitted in the channel. I bought 15mm external diameter and this lay quite well half in and half out of the channel. I've attached a photo of how it looks. When I first went out to see if it made a difference, I was disappointed that I could still hear the whooshing but I then noticed that a bit of tubing had lifted it up. I put a finger on it and it was a true revelation! The noise stopped instantly. I had discovered the source of my irritation. For whatever reason, the window seal in the driver's door was not providing a proper seal.

I got my wife to drive the car while I did the same with the other doors. It turned out that the windows in the passenger door and the rear door on the passenger's side were also noisy. The rear door behind the driver's seat was fine. I have spoken to the parts department at my nearest main dealer and was not surprised to learn that the seals are over £100 each and that the labour to replace just one would come to about £200. I don't think this is an option! So, I am sourcing some slightly smaller diameter tubing which I think will be less obtrusive and which I hope will still perform the same role as my original tube.

I know that this all seems highly unlikely given Lexus's reputation for the quietness of their cabins. I am as bemused by this as was the man I spoke to in the parts department. He had never come across this problem before. All I can say is that I have incontrovertible evidence now that I have not been imagining the problem. I have been able to make a recording which clearly demonstrates the difference when the tubing makes a snug fit and when a little bit of it lifts up. Even my wife, who has been watching my antics in amazement for the last few weeks, now admits that the difference is stark.

I hope this may be of some interest to somebody else who is unfortunate enough to experience the same problem at some point in the future. I cannot believe that I can be the only person in the UK to have worn window seals?

royzels · January 12, 2019

To Olliesgrandad....Sorry for going off the subject....but I am ex Police....be nice to talk to you......................... Once again sorry for going off the subject... Royzels

Herbie · January 12, 2019

1 hour ago, Rhub said:

I have been able to make a recording which clearly demonstrates the difference when the tubing makes a snug fit and when a little bit of it lifts up

It would be interesting to hear that Rob, if you wouldn't mind uploading it. Very glad that you got it sorted in the end though

ColinBarber · January 12, 2019

2 hours ago, Rhub said:

I hope this may be of some interest to somebody else who is unfortunate enough to experience the same problem at some point in the future. I cannot believe that I can be the only person in the UK to have worn window seals?

If this wasn't an RX then I'd suspect a previous owner had roof bars installed which clip around the frame and press against the seals, distorting them. However your RX should have rails and therefore wouldn't have had that type of roof bar installed.