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Passenger dash rattle near the vent. Only occurs when going on rough roads. The way to reproduce it is by tapping the area above the vent. From what I hear could be from the vent itself. I lubricated with WD silicon, I have also temporary restricted all movement of the flaps in the vent but still can reproduce it. Anyone who has figured this one out? Model RX 450h 2018
That looks like the passenger side vent. I would next check inside the glove box, and the glove box mount itself, plus the cabin air filter assembly for loose parts etc.
Drop down the glove box like when replacing the cabin air filter and check if you can see or access the vent assembly from below.
Look inside the vent above it (on the top of the dash) with a flashlight to see if anything appears loose or if a foreign object is inside it.
If you don't know how to replace the cabin air filter there are many youtube videos.
Last edited by Clutchless; Jun 4, 2026 at 06:56 AM.
Alright, so I removed the filter cover but was still buzzing. I saw that when I press the defrost trim it stopped, removed that but buzzing continues. Even without the plastic trim when I put pressure on top of the whole the vibration stops. I guess it is something internal in the dash…
Time to start sticking duct tape on suspect areas under the dash and hope it helps reduce the rattle. That is all I have, as nobody wants to take the dash apart.
Passenger dash rattle near the vent. Only occurs when going on rough roads....
Based on your description of the issue, and considering that the Lexus RX is generally a rattle-free vehicle, my guess is that a foreign object is stuck somewhere in the HVAC system. The hard part will be figuring out exactly where it is.
Although my RX has been essentially flawless for the past 6 years, I do get intermittent and annoying rattles in the dash from time to time.
They usually show up in the colder months and are very difficult to pinpoint and fix. I have put small strips of double sided black hockey stick tape on some areas of the dash, and I have used a small section of weather striping foam where the dash meets the front windshield. It works most of the time and then a random rattle shows up.
I never put anything on my dash so I am pretty confident that nothing has fallen in. I will continue to do battle but sometimes the music just gets turned up a little more.
Dash rattle near vents
