2016 RX450H squeaky rear suspension and lane assist issue

[John Walker]

Hi everyone, recently bought my 5th Lexus which it happens to be also my first SUV, RX450h Luxury with 78.000 miles, full Lexus service history and very well maintained overall. 
 

A few months after I realised that there is a squeaky noise from the right rear when I go over bumps. Initially I thought it could be the rear seats or something from the boot. After checking it carefully I realised it comes from the suspension. I ve heard about this issue from another two people. Did anyone encountered this problem? Would Lexus sort this out on warranty? 
 

Second issue started to appear when the temperatures got below 3 C degrees, the lane assist system won t recognise the lanes almost at all, it works only for short periods of time. The checked the two from sensors and they are clean. 
 

And there is actually a third issue, my windows get foggy when i use the climate control on recirculating with AC on, this never happened in any of my cars before unless the AC wasn’t working. 
 

Very frustrating after I ve had high mileage Lexuses without absolutely any issues. 
 

 

[PCM]

Oh dear...

If it's from Lexus with a warranty, I would book it in for free fixes!

[08ISF]

My 2016 RX450h does the squeaking thing but only on certain bumps, always has. I haven't raised it with Lexus as the chances of them being able to trace it are low and it doesn't bother me.

The issue with the lane assist sounds like condensation somewhere it shouldn't be. You say they checked the front sensors. Which sensors? I thought the LKA worked on the  camera at the top of the screen, which has been known to suffer from condensation. Again this is going to be difficult to trace as the minute they put it in the workshop it will warm up and the condensation will disappear.

Windows fogging  on recirc sounds like the ac compressor being held off. Do you run the car in ECO mode? This apparently widens the tolerances on the climate control so that might account for the fogging. ECO mode doesn't seem to make any difference on fuel so I don't bother with it.

There was a time when you could just chuck  the car back at Lexus and say fix it, not so now, they often want £180 just to look at it unless  something is obviously broken.

Let us know how you get on .

[Chunkyman2]

On 12/11/2022 at 11:06 AM, John Walker said:

A few months after I realised that there is a squeaky noise from the right rear when I go over bumps

I have had a similar issue with my 2017 RX450h F-sport. It passed a recent MOT but the creaking noise was still there on the rear right hand side when I went over raised traffic control ramps. My local Lexus garage checked it out and replaced (yesterday) both L and R training arms, bolts and bushes as both were reportedly showing signs of wear. It has cured the problem. 

The main issue however is that the bushes are not covered under the Lexus relax warranty and Lexus do not supply the bushes only so you have to buy the whole inclusive arm. I complained bitterly but the best my local garage could do was to reduce the labour costs as much as possible. I still had a bill for £1,100. Lexus turned down a warranty claim despite requests to reconsider from the garage service manager. The car has 54,000 miles, I have had 4 Lexus SUVs over the past 15 years and have never encountered this before.

[Bluemarlin]

On 12/11/2022 at 11:06 AM, John Walker said:

A few months after I realised that there is a squeaky noise from the right rear when I go over bumps. Initially I thought it could be the rear seats or something from the boot. After checking it carefully I realised it comes from the suspension. I ve heard about this issue from another two people. Did anyone encountered this problem? Would Lexus sort this out on warranty?

Spray any bushes/rubber components with silicone lube and see if that helps. A spraying of something like ACF-50 on the suspensions parts might possibly help too.

As pointed out above, bushes aren't covered by the Relax warranty. However, they can also quickly show signs of wear, whilst still being perfectly serviceable, and able to last for many miles/years to come. I was told last year that mine looked worn, and was quoted around £2k to replace the arms, but I just sprayed some lube and it wasn't mentioned at the last health check.

It's also worth noting that the 10yr+ warranty doesn't specifically exclude bushes like the Relax warranty does, and I read elsewhere on the forum that someone got their control arms repaced under this warrranty. So, anyone with worn looking, but not seriously degraded bushes, might want to try and keep them serviceable until they get beyond the 10yr mark.

[John Walker]

Thank you for all your replies guys. I called my local Lexus garage in Twickenham and they said I might have to pay for the first hour of labour (£190) if the issues i have are not covered by the warranty which I think it s ridiculous and it spoils the whole Lexus ownership. This is my 5th Lexus and never had any issues.

Then I decided to try my luck with other dealership and just to find out that Lexus Guildford won t charge me anything no matter if the issues i have are covered or not by the warranty so I scheduled the car for a check next week. If you feel like your local dealership is ripping you off, go somewhere else. 
 

My friend had the same car with the same issue, it was fixed by Lexus Twickenham under the warranty and they didn’t tell him about any extra charges in case the warranty wouldn’t have covered it. BUT he bought the car from them for a hefty price (second hand) 

 

I m also very annoyed that my windows are getting foggy on a longer journey despite the fact that my AC is always on and on recirculating as i don t like to smell the pollution from outside. Does anyone else have this problem? 
 

More recently discovered that a strange sound it s coming when the petrol engine is cold (at low speeds) feels like the exhaust is not in place or something like that. 
 

I also read on this forum a quite a few people have problems with the panoramic roof, water getting in. My car had this issue and apparently it was fixed on warranty by the previous owner. The water damaged the sat nav system and they had to change the whole thing. This is not the Lexus i got used to.

I previously had a 2012 gs450h, sold it at 210k miles and NEVER had any issues. One of my other cars was a 2016 GS300h that i sold at 326k miles and YES you read correctly, 326k miles, i was the second owner, it was previously a company car, again no issues at all and you would never be able to guess the mileage. 
 

I had lots of faith in this brand but I might change my mind. Next on the list is a 2020 RX Takumi, if that is as well a disappointment….i might go back to a GS or an LS. 

[John Walker]

On 12/12/2022 at 8:35 AM, 08ISF said:

My 2016 RX450h does the squeaking thing but only on certain bumps, always has. I haven't raised it with Lexus as the chances of them being able to trace it are low and it doesn't bother me.

The issue with the lane assist sounds like condensation somewhere it shouldn't be. You say they checked the front sensors. Which sensors? I thought the LKA worked on the  camera at the top of the screen, which has been known to suffer from condensation. Again this is going to be difficult to trace as the minute they put it in the workshop it will warm up and the condensation will disappear.

Windows fogging  on recirc sounds like the ac compressor being held off. Do you run the car in ECO mode? This apparently widens the tolerances on the climate control so that might account for the fogging. ECO mode doesn't seem to make any difference on fuel so I don't bother with it.

There was a time when you could just chuck  the car back at Lexus and say fix it, not so now, they often want £180 just to look at it unless  something is obviously broken.

Let us know how you get on .

I run my car on ECO but after you told me i tried keeping it in Normal and then Sport, i also made sure the climate control setting is on Normal/ Fast and not on Slow. Nothing seemed to work. 

[John Walker]

2 hours ago, Bluemarlin said:

Spray any bushes/rubber components with silicone lube and see if that helps. A spraying of something like ACF-50 on the suspensions parts might possibly help too.

As pointed out above, bushes aren't covered by the Relax warranty. However, they can also quickly show signs of wear, whilst still being perfectly serviceable, and able to last for many miles/years to come. I was told last year that mine looked worn, and was quoted around £2k to replace the arms, but I just sprayed some lube and it wasn't mentioned at the last health check.

It's also worth noting that the 10yr+ warranty doesn't specifically exclude bushes like the Relax warranty does, and I read elsewhere on the forum that someone got their control arms repaced under this warrranty. So, anyone with worn looking, but not seriously degraded bushes, might want to try and keep them serviceable until they get beyond the 10yr mark.

The thing is that my car was just serviced at Lexus Twickenham but they didn’t say anything about the back suspension. 

[Bluemarlin]

15 hours ago, John Walker said:

The thing is that my car was just serviced at Lexus Twickenham but they didn’t say anything about the back suspension. 

In which case the suspension may be fine, in that it's not actually faulty, and a bit of lubrication may get rid of the creaks. Can't hurt to try.

As for the foggy windows, is it possible that you still have a leak somewhere? Check the carpets for damp, and lift all the covers in the boot to see if there are any signs of water ingress.

You might also want to try switching your ac to outside air now that it's colder. Recirculation just keeps any humidity  within the car, which can cause your windows to fog up, especially in cold and damp weather. Your pollen filter will keep the outside air clean from any pollution.

[wardy1]

You shouldn’t use recirculation in the winter or cold weather as it traps the air inside the car. Any condensation will take a lot longer to clear up. Your ac acts as a dehumidifier but trapping the air in the car means the moisture has nowhere to go.

[rayaans]

To be honest the squeaky rear suspension over bumps has been the case on all my RXs since new. I don't think there's anything wrong and it's not got worse.

As above you shouldn't use recirculation in winter. Additionally under 5 degrees or so the condenser stops working as it's at risk of freezing. 

 

 

[John Walker]

You guys are right, when it s too cold outside I shouldn’t use the ac on recirculation. I left it today on Auto and it run most of the time taking air from outside and it was perfectly fine. However when there is a very smoky car in front i would get some smell inside. My cabin filter is brand new. But it is what it is, the air filtration is not brilliant, i can live with that. 
 

The lane assist however doesn’t work almost at all (does come on sometimes) and i wonder if it has to do with what 08ISF said here, that it suffers from condensation. 
 

Will check for any water ingress although i hoover the car myself regularly and didn’t see any water. I also have rubber mats. 

[John Walker]

UPDATE 

The car just been checked at Lexus Guildford and I have to say the customer service is 10/10, impeccable! 
 

The car had a full free check all around. The suspension is perfectly fine, they applied some lubricant which I m not sure how long it will hold but the noise is gone for now. 
 

The lane assist didn’t show any errors on their computer and they said it might be because of the weather and if it still doesn’t work in some time I should come back and they will do a longer test drive, take some videos and send them to Lexus (in Japan i guess). This morning it worked for a few miles and on my way back worked all fine. So very confusing. However i did get to test drive the amazing LC500 convertible (what a CAR) and the lane assist had the same issue. It was a 2 hours test drive. 
 

Other than that the car is great condition. Had an AC disinfection as it was on offer for £35, i wanted to change the AC gas but they said it wasn’t necessary (£79 on offer) 

 

I also did a short test drive with the 2022 RX450h Takumi and i have to say that I wasn’t blown away..except from the few extra optionals compared with mine (mine is a Luxury) nothing special. The seats seemed to be a bit softer and i really didn’t like that they made the display touchscreen and moved it closer, i like the screen in the pre facelift as it s a bit further and makes the car a bit more spacious. I sat in the F Sport model and i was pleasantly impressed with how supportive are the seats. They seem stiffer at the beginning but I assume that after a long drive for those with back problems, might be a better option. 

[Bluemarlin]

22 hours ago, John Walker said:

The car had a full free check all around. The suspension is perfectly fine, they applied some lubricant which I m not sure how long it will hold but the noise is gone for now. 
 

 

Well at least you know the cure if it reappears. As I mentioned earlier, I give the complete underside a spray of ACF 50 annually, which not only seems to keep any creaks at bay, but has the added benefit of helping to protect against rust.

[GSLV6]

I had similar issues with the suspension and needed trailing arm links replaced.  As mine is still low mileage despite being 8 years old, Lexus kindly did this under warranty for me.  With such a heavy car, bushes don't seem to actually last that long and as the bushes themselves are not considered economic to replace, they replace the whole link.  One of my OEM ones failed after just 3 years.  I have two that were noted as having splits in them which I'm, monitoring and will probably have repaired at the next service.  £270 a pop so not cheap and looks like I may have to pay for this set.