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I'm taking my 2018 LC 500 into the dealer tomorrow for the 4th time. Despite having a legendary Diagnostic Technician, they haven't been able to solve my tapping noise problem. So far they have twice replaced the 3rd brake light, replaced all the rear window alignment pins, tried adding padding (I believe), and put 200+ miles on the odometer. Tomorrow a Lexus Specialist is flying up from LA. Here's hoping!
I've attached an MP3 sound file which I recorded recently while my wife was driving. The recording begins just as we slow down from 50 MPH approaching Boonville, CA on HWY 128. The recording continues as we slow to 40 MPH, then 30 MPH through Booneville, then back to 40 MPH, and finally 50 MPH as we leave Booneville. You may need to turn the volume up as I recorded this sound with my iPhone.
In anticipation of my Lexus appointment tomorrow, I would very much appreciate it if SuperGT and/or Oilman would let me know if this is the sound that you are hearing. Also, what model year is your LC 500 , and do you have (as I do) the Carbon Fiber roof? Thanks - if I get a solution I'll be sure to post it!
I'm taking my 2018 LC 500 into the dealer tomorrow for the 4th time. Despite having a legendary Diagnostic Technician, they haven't been able to solve my tapping noise problem. So far they have twice replaced the 3rd brake light, replaced all the rear window alignment pins, tried adding padding (I believe), and put 200+ miles on the odometer. Tomorrow a Lexus Specialist is flying up from LA. Here's hoping!
I've attached an MP3 sound file which I recorded recently while my wife was driving. The recording begins just as we slow down from 50 MPH approaching Boonville, CA on HWY 128. The recording continues as we slow to 40 MPH, then 30 MPH through Booneville, then back to 40 MPH, and finally 50 MPH as we leave Booneville. You may need to turn the volume up as I recorded this sound with my iPhone.
In anticipation of my Lexus appointment tomorrow, I would very much appreciate it if SuperGT and/or Oilman would let me know if this is the sound that you are hearing. Also, what model year is your LC 500 , and do you have (as I do) the Carbon Fiber roof? Thanks - if I get a solution I'll be sure to post it!
I had already listened to your clip last year, same sound as mine. 2018 with carbon roof. As an FYI, I had my wife sit in the back and when she pressed upwards gently on the ceiling panel the cracking sound stopped for 15-30 minutes. Comes back every time after that. Thanks.
Thanks for the "noise" recording. Yes, mine sounds very much like yours did in the recording. Mine is a late March production 2018 model with the glass roof.
The Lexus tech here has now had the car for six days. Replaced the third brake light, worked all the rear window alignment pins, and tightened the brace under the rear passenger side seat. Still has the noise. The Lexus "gurus" told him today that it is likely two panels that are rubbing together that make the noise because the noise is constant..ie, doesn't come and go. Lexus tech will try to isolate the two panels tomorrow. I have my doubts at this point.
I am more than unhappy that the car looks like a million dollars but sounds like an old Ford pickup.
My last seven cars have been Bimmers. Never had all the squeaks and rattles like this Lexus. So much for Japanese engineering.
I also have a 1997 Lexus ES 300, and I kid you not: on smooth roads the ES has fewer rattles than my 2018 LC 500. On rough roads the ES has developed plenty of rattles - however, the LC 500 tapping noise is unbearable on ALL roads. This noise has ruined every summer trip that I've taken.
Last edited by CANorthCA; Aug 26, 2019 at 07:12 PM.
Last week Lexus flew a Factory Field Specialist up to my local Lexus dealer. I drove him around on local roads where over recent weeks I have repeatedly heard the tapping noise. Finally, after nearly 2 hours and 100 miles of driving, the noise kicked in. The Factory Field Specialist was then able to demonstrate the tapping noise in all its glory to my dealer's Diagnostic Specialist. Together they were able to determine the cause of the tapping noise, and to arrive at a solution.
The tapping noise was due to intermittent contact between the 3rd brake light's mounting bracket and the rear window glass. In fact, they found a "smoking gun": the metal bracket had registered marks on the glass. I believe the difficulty in reliably reproducing the noise was due to the fact that the tapping varied with thermal expansion of the rear glass urethane adhesive (and possibly with flexing of the car body over twisty roads).
The solution to the problem was to replace the rear window glass with new glass to which the 3rd brake light bracket is directly bonded. Although there is no TSB, Lexus has indeed created a new rear window glass part.
Since the rear window glass was replaced last week, my wife and I have driven more than 300 miles in the car - in 90+ degree weather over winding roads with sharp curves and steep grades - without hearing a peep from the rear window glass. We believe the tapping noise problem is solved once and for all.
(For anyone who may be wondering if this repair is applicable to a noise that they are currently hearing, I have attached the latest MP3 file recorded prior to the repair.)
Last edited by CANorthCA; Sep 3, 2019 at 12:35 PM.
Thanks for that update. I'm still going to pursue the avenue of it coming from the ceiling liner since the noise stops when one presses upwards on it gently, something that couldn't be related to the brake light I presume. Will keep everyone updated on my experiments.
Thank you so much for your detailed explanation and fix. It may come in handy if my replacement third brake light replacement doesn't work. But my horror story goes far beyond the third brake light. Once the tech replaced the brake light and took it for a test drive, he heard a noise originating from low in the back floor area. Long story short (since they've had the car three weeks now) they determined that a weld must have broken between the rocker panel and another panel on the car that was making the rubbing, scrapping noise. So now the Factory Field Specialist is to come next Tuesday to investigate himself. Talk about a total cluster. Can it get worse?
I will have to wait to hear definitively that he agrees the problem is a weld. If so, how to fix an internal spot weld failure? Heaven knows. 4000 miles and it is falling apart.
I have no idea how to proceed from here.
NOISE SOLVED! As there are several potential noises that may appear to be the same/similar, I understand that their sources may differ. Having said that, I was finally able to isolate and fix the one in my car. From the beginning, the noise sounded like hard plastic rubbing gently against metal when driving on anything but a perfectly flat road surface. The noise stopped when pressing gently upwards on the ceiling liner but returned after 15-30 minutes. If your car demonstrates the same type of noise (coming from the upper rear ceiling liner area) then this remedy could work for you. There are several molded plastic pieces (highlighted in red) that are part of the liner frame (as pictured). Those pieces all have small felt pads to prevent the plastic from ''squeaking'' against the metal roof frame. It appears that there is more area that actually comes in contact with the metal than only the felt pad areas. So I cut several pieces of thin foam sheets with adhesive backing and stuck them over all of the molded plastic pieces to cover a much wider area than the felt pads alone did. The perceived rubbing/rattle/cracking noise has now dissapeared.
After extensive testing, the FTS figured out what the issue was with my rattling noise in the rear. Apparently it was something in the strut tower on the rear driver's side. What he told the service manager (which he then told me), was that while they were test driving my vehicle (with all the interior rear panels removed), he noticed some movement on the driver's side rear tower. He compared it to the passenger rear side, and there was some noticeable difference in the movement (typically it's not supposed to be moving). They don't know exactly what it is within the strut tower, but they are replacing the entire component, and everything within it. Since then, I have received my vehicle back (with the original parts reinstalled), until all the parts come in from Japan. Once they replace the strut tower, they will send my original one back to HQ in Japan for further R & D to pinpoint the issue.
Shortly after they discovered the issue with mine, they had apparently heard of another exact same issue on another LC at another dealer down south.
I recommend any of you that are encountering the same rattling noise from the rear, to have it checked out and mention to them to also verify the rear strut towers.
3 long weeks after having my car at the dealer, I'm glad they managed to at least uncover the cause. The final component I'm waiting for now is the spring. Once they receive that, then they will schedule me in to replace the entire strut area.
**I was thinking that if they already will be doing that, then maybe have them replace the springs with lowering ones - preferably F Sport applications (like the ones they had for the IS models) - I doubt there are any for the LC though
Can you share the name of the dealer who did your repairs?
I have the same issue “a loud clicking sound coming from the rear passenger side (towards the bottom) - it's not the seat” did they figure what it was?
I don't blame you. I was supposed to go for a test drive with the head tech at my dealer last week - decided not to. Between the fuel pump replacement and this rattling sound, my car's been at the dealer for a total of 6 weeks. I'm not sure I want to leave it there any longer.
So the issues I have:
- a completely replaced strut tower on the rear driver's side - still making noise
- third brake light insulation - still rattling in the rear upper portion of the cabin
- a loud clicking sound coming from the rear passenger side (towards the bottom) - it's not the seat
I haven't enjoyed the car much, and I'm not sure I'm willing to leave it any longer at the dealer. Maybe by waiting a little longer, more TSB's will come out, which would allow the dealers to come to quicker solutions.
I have the same issue “a loud clicking sound coming from the rear passenger side (towards the bottom) - it's not the seat” did they figure what it was?
I have the same issue “a loud clicking sound coming from the rear passenger side (towards the bottom) - it's not the seat” did they figure what it was?
They managed to change out the entire strut tower on both sides. They also adjusted all of the links in the multilinks. Ever since then - no rattling.
