Weird intermittent brake noises when decelerating: 2015 RX 350 F SPORT AWD
11-15-23, 04:51 PM
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Weird intermittent brake noises when decelerating: 2015 RX 350 F SPORT AWD
Hi, just got back from the dealer--couldn't get this whirring, whooshing noise to manifest on a 15-min test drive with the technician, but of course, on the way home, it happened.
Short video below: I brake gently from approx 30 mph and I heard this noise, and then, a few seconds later when I tried braking again, there is no noise.
2015 RX 350 F SPORT AWD, 122,000 miles, bought used with 98k miles in 4/2022. This is my first Lexus. I've never heard this noise with any other vehicle before, including the brand-new Lexus UX hybrid loaner that they gave me while my car was being serviced.
This has been happening intermittently for about 1-2 months, that I've noticed. I've had the car for about 1.5 years. Is this considered a normal Lexus braking noise?
Sometimes, also while decelerating, I also hear a gurgling or rushing of what sounds like liquid from inside the dash. I've tried turning off the AC, and it still happens, so it doesn't seem to be the AC--although the AC also gurgles on its own, which seems to be an unrelated issue.
Further, I've noticed that these brake/deceleration noises only tends to happen after the car is warm and has been driving for 20 min or more, and they occur at low speeds.
Lastly, there is another, much louder noise when braking that is much more alarming (NOT IN THE VIDEO ABOVE), and that's what actually caused me to take the car into the dealer--but the technician told me that the clunking is, without a doubt, the sound made when the ABS engages all four wheels, since the car is AWD. He thought it was normal, although he commented that maybe the system was just a bit old. He said he'd have to find another AWD RX and trigger the ABS to compare! I don't have a video of that noise at this time, but can make one and add it to this post if anyone wants to hear it. At least when the clunking is happening / the ABS is being triggered, the brakes themselves did not lock up and the car does brake straight without pulling to either side, so it seems that despite the awful clunking noises, the ABS seems to be working. I've just never experienced this personally with ABS before in any other car--I'm used to a gentle "fluttering" or shuddering feel on the brake pedal that is very fast, not a series of slower "thuds." The first time this happened, I actually thought that some transmission component had fallen off the car's undercarriage--it was that loud!
Notably, we had just triggered the ABS probably 7-8 times prior to this video, so I don't know if setting off the ABS so many times in a row would explain the video noise? Prior to going to the dealer, now that I think about it, the whooshing/whirring/gurgling noises tended to happen with the brakes at low speeds JUST AFTER the clunking noise had happened if I had hit the brakes hard.
I just want to make sure I'm not driving around with brakes that are going to fail in an emergency! Functional ABS seems important!
The technician checked my pads, rotors, and brake fluid, and everything seems to be ok. Technician did not think it was wheel bearings.
Not sure what else it could be--would love to hear any thoughts. Thank you in advance for your help!
Short video below: I brake gently from approx 30 mph and I heard this noise, and then, a few seconds later when I tried braking again, there is no noise.
2015 RX 350 F SPORT AWD, 122,000 miles, bought used with 98k miles in 4/2022. This is my first Lexus. I've never heard this noise with any other vehicle before, including the brand-new Lexus UX hybrid loaner that they gave me while my car was being serviced.
This has been happening intermittently for about 1-2 months, that I've noticed. I've had the car for about 1.5 years. Is this considered a normal Lexus braking noise?
Sometimes, also while decelerating, I also hear a gurgling or rushing of what sounds like liquid from inside the dash. I've tried turning off the AC, and it still happens, so it doesn't seem to be the AC--although the AC also gurgles on its own, which seems to be an unrelated issue.
Further, I've noticed that these brake/deceleration noises only tends to happen after the car is warm and has been driving for 20 min or more, and they occur at low speeds.
Lastly, there is another, much louder noise when braking that is much more alarming (NOT IN THE VIDEO ABOVE), and that's what actually caused me to take the car into the dealer--but the technician told me that the clunking is, without a doubt, the sound made when the ABS engages all four wheels, since the car is AWD. He thought it was normal, although he commented that maybe the system was just a bit old. He said he'd have to find another AWD RX and trigger the ABS to compare! I don't have a video of that noise at this time, but can make one and add it to this post if anyone wants to hear it. At least when the clunking is happening / the ABS is being triggered, the brakes themselves did not lock up and the car does brake straight without pulling to either side, so it seems that despite the awful clunking noises, the ABS seems to be working. I've just never experienced this personally with ABS before in any other car--I'm used to a gentle "fluttering" or shuddering feel on the brake pedal that is very fast, not a series of slower "thuds." The first time this happened, I actually thought that some transmission component had fallen off the car's undercarriage--it was that loud!
Notably, we had just triggered the ABS probably 7-8 times prior to this video, so I don't know if setting off the ABS so many times in a row would explain the video noise? Prior to going to the dealer, now that I think about it, the whooshing/whirring/gurgling noises tended to happen with the brakes at low speeds JUST AFTER the clunking noise had happened if I had hit the brakes hard.
I just want to make sure I'm not driving around with brakes that are going to fail in an emergency! Functional ABS seems important!
The technician checked my pads, rotors, and brake fluid, and everything seems to be ok. Technician did not think it was wheel bearings.
Not sure what else it could be--would love to hear any thoughts. Thank you in advance for your help!
11-15-23, 06:32 PM
#2
Pole Position
Listening to your vid a couple times, my thought is a light bearing noise. I'd suspect a rear bearing as those tend to wear vs the front ones.As far the clunking noise, after hitting the brakes hard, as the suspension compresses & rebounds, I'd be looking at the strut mounts,struts, ect. Thats if the caliper mounting bolts & the caliper slider pins are tite as well as the pad shims/clips are installed correctly. Possibly have a shop w/ a alignment rack or a 4 post drive on rack where they can pull down on the front & rear of the vehicle. I'd also hit up a indy shop that works on Toyota/Lexus vehicles, such as a Gregs Japanese shop, ect. A few ex Toyota dealer tech's work in indy's btw. California, at times we miss it down there......
11-16-23, 04:18 AM
#3
Moderator
Welcome to CL.
I agree with Felix. Other stuff needs to be inspected. That dealer tech was not very good at his job.
Also I would get the brake fluid flushed as brake fluid absorbs water and it should be done every few years. You could have a failing brake system component and they can be expensive.
Have your brake caliper slide pins lubricated too in case they are sticking.
Regarding the gurgling noise, it could be the brakes, but also get your A/C drain checked to be sure it is not clogged, same with the sunroof drains. Also check your coolant level. It may be a good idea to change the coolant at this time as it is about due according to Lexus and the noise could be related to air in the system.
I would get an opinion from a well regarded independent repair shop. They will be much more familiar with older vehicles. Dealer techs are really most familiar with the newer cars that they repair under warranty. Use this link to find some highly rated independent repair shops near you. It is a database of shops rated by listeners of the Car Talk Radio Show. It lets you select city and state and even car manufacturer. https://www.cartalk.com/mechanics-files
Then cross check any shops you like on Yelp or Google for more current reviews as some of the data may not be current.
I agree with Felix. Other stuff needs to be inspected. That dealer tech was not very good at his job.
Also I would get the brake fluid flushed as brake fluid absorbs water and it should be done every few years. You could have a failing brake system component and they can be expensive.
Have your brake caliper slide pins lubricated too in case they are sticking.
Regarding the gurgling noise, it could be the brakes, but also get your A/C drain checked to be sure it is not clogged, same with the sunroof drains. Also check your coolant level. It may be a good idea to change the coolant at this time as it is about due according to Lexus and the noise could be related to air in the system.
I would get an opinion from a well regarded independent repair shop. They will be much more familiar with older vehicles. Dealer techs are really most familiar with the newer cars that they repair under warranty. Use this link to find some highly rated independent repair shops near you. It is a database of shops rated by listeners of the Car Talk Radio Show. It lets you select city and state and even car manufacturer. https://www.cartalk.com/mechanics-files
Then cross check any shops you like on Yelp or Google for more current reviews as some of the data may not be current.
Last edited by Clutchless; 11-16-23 at 04:41 AM.
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