Dash Rattle and Vibration Noise

I couldn't hear anything on the video, but have you checked if it's coming from your glovebox. You might try emptying it or rearranging the items and see if the noise disappears or changes.

 

If you ever have passengers in the front passenger seat, check that the seat belt buckle is not twisted and rattling up against the pillar. That may sound like it's coming from the right front dash.

 

I can't hear the rattle in your recording, but I wonder if it's the same as mine. I've got one that's on the driver's side. Sounds like two pieces of plastic just barely rattling(almost buzzing) against each other but only in a particular set of conditions. I can only hear it in EV with everything off(radio, HVAC, windy day, etc). Even the ICE at idle tends to cover it up. It's not linked to any specific action(acceleration, braking, terrain), so I think it's a form of sympathetic vibration. I can almost reproduce it at will; I succeed maybe 75% of the time when I try. But I haven't been able to pinpoint it beyond "somewhere inside the dash"

I've considered taking it in, but I'm afraid the dealership would have to rip apart the dash to try and find it, and I could end up with them not fixing it and adding even more rattles if clips, tabs, or slots get broken during the work. Plus I can't really be without the car for the multiple days it would likely take them to try and find it/fix it. I think I've decided to just live with it and just turn on the radio or something when it gets annoying. Thankfully you can't hear it at highway speeds, so that's not an issue.

If I ever decide to do the ambient light color swap from blue to red, I'll probably try to find and fix it myself since I'll have to disassemble a big chunk of the dash anyway.

 

the dealer might have to pull the whole dash apart to find it, then you might have even more rattles after they reassemble it

 

I had a very similar buzz on my Gen 4 and I traced it down to the speaker grill on top of the dash. I took the grille off and put a little foam padding in, replaced the cover and it disappeared.

It's a bit of a stretch, but if you can get a passenger to reach forward and press down on the grill to see if that stops it, if so try the above.

 

Rattles are "tough".

FWIW Sometimes one thinks the rattle is at the right front and it is actually at the left rear.
Just perhaps it is not in the interior but in the wheel well/ liner or undercarriage...there are plastic panels with push-in retainers in those two areas.

Some good advice is driving with a passenger who can apply pressure here and there and listen around.
That's the first step, find the area that is rattling.
There are tools for rattle locating including a stethoscope (inexpensive) and electrical (expensive).
If you could vibrate the car, I not so how to accomplish that, in the garage creating the rattle and fit yourself under the dash to poke around, well, that could help isolate the rattle greatly.

Lastly, I could agree dash disassembly could create more issues.
If this avenue is chosen, I would DIY as I have great hesitancy of shop labor and flat rate taking quality assembly time.
Foam, Velcro, felt, and double-sided stick tape are you friends

Wishing you the best of luck.
Rattles suck

PS Let us know what you find.

 

I have a 2023 prime, and I think we might have a similar rattle. I hear the same buzzing noise that sounds like two pieces of plastic just hitting each other, or maybe a thin piece of metal vibrating in the open. Mine is pretty audible from the drivers seat, and sounds like it could be coming from either the cover for the forward recognition (behind the rear view mirror) or from the center dash behind the infotainment. I've tried to apply felt tape around the forward recognition cover to no avail - I did remove and replace that early on in order to use an adapter to power a dashcam, but I don't see visibly damaged clips, and applying pressure while the vehicle is in motion doesn't prevent the rattle. When in the driver's seat I hear it on my right, and the left when in passenger, so we're fairly certain it's at least bouncing in from the center, if not originating.

I'm also hesitant to take it to a dealer, as it's possible it's not a covered defect, which would be expensive and potentially not even a solution. My rattle rears it's head on textured roads, is loudly audible over other road noise, the ICE, and even the radio at like 20-30 volume.

My next steps are probably to remove my dashcam and see if that's the cause of the rattle.

 

You can sometimes locate these more easily with a stethescope, by placing it on parts you think are generating the noise. Inside the engine compartment, there are "mechanics" stethescopes with a long metal probe you can hold against them, but for the interior a normal stethescope is probably better. And would get into the passenger side and move it around to help locate. I've found the car has a lot of rattles and creaking noises. Although yours might be more severe. The difference between a 60-70K car and a 40K car, and cheaper interior compared to a Lexus, Volvo, etc. So just imagine every rattle is the sound of a pennies dropping into jar as you save money on the cheap interior.

 

Hey there, I have experienced this rattle sound quite a bit in the beginning of my ownership, but recently (4 months in) I have noticed it has almost went away. From my experience, my rattle was specifically coming from the front left corner on the dash, at first I thought it was my loose temporary registration but later found out that wasn't the issue. As the noise went away, I simply stopped researching about this rattle but I do wish you a good luck and will keep track of this post. Cheers!

 

I've also had a plastic rattle sound and I've narrowed it down to the 3 pieces of plastic behind the rearview mirror. They cover the mirrors mount to the windshield and alternate rattling depending on which one I've nudged back into place. Seems like there's always one of them loose that rattles loudly at higher speed and/or rough roads. I haven't installed a dashcam or removed those covers at all. I hesitate to remove them completely for further troubleshooting - I don't want to make it worse by breaking anything.

Can any of you confirm that's the same place you have a rattle?

 

I initially thought this was my issue, but it's not likely to be the main cause for my vehicle. I did an extensive test over the past weekend - sat in the passenger seat with a stethoscope while someone else repeatedly drove back and forth over a stretch of road that has just the right texture to cause the vibrations.

My rattle has a persistent buzzing over some roads, annoyingly including a textured part of my daily commute. There is a second, much louder rattle/buzz that is accompanied by some bigger bumps in the road, like connecting parts of asphalt, some potholes, rapid deceleration on a textured road, etc. This louder rattle sounds like it comes from multiple parts of the dash/car at once, while the primary rattle seems more localized.

• Main rattle wasn't coming from the plastic cover behind the rearview mirror (forward cognition cover). I did remove this to install a dashcam, but have since went and lined every piece of plastic that touches something else (other than the latches) on the cover and smaller panel with foam tape. The primary rattle is still present even with the entire cover fully removed, though I wouldn't rule out it contributing the louder second type of rattle.
• With the stethoscope, I've noticed the following parts seem to present the most rattle/noise that closely matches the audible rattle:
  • Passenger side door, particularly near the armrest
  • The retention clips for the sun visor on both the driver and passenger sides
  • The steering wheel column

If I unlatch the sun visors, a lot of the primary rattle becomes almost imperceptible. The second type of rattle is still present, though maybe just slightly subdued. I'm guessing certain types of road texture/vibration travel up through the car, including up above to the roof and through the clips for the sun visor latch. When connected, the sun visor acts as an amplifier for the vibrations. More powerful vibrations caused by deceleration, bumps in the road, etc. travel through all the potential rattle spots.

For now, I'm probably going to leave the sun visor unlatched - I'm not sure if foam tape would hold up on the latch, as I swivel the visor around relatively frequently. Perhaps there's some other product that could dampen the vibrations while not impeding the function of the visor? I can't imagine this rattle is unique to this car. For the louder "surround sound" style rattle, I might just have to deal with it - it's probably multiple interior panels/components, and I'm hesitant to know if this would even be covered in any sort of year 1-warranty. Maybe it's worth a shot?

Maybe you guys can give this a shot and see if you notice any difference with the visors latched/unlatched?

 

I think I found my rattle/buzzing, but those of you with the same problem are not going to like the fix.

In my car, it appears to be a relay deep behind the dash, bolted to the body.

I have my dash out for my mirror and lighting upgrades, and I could hear it more clearly. I drove around to make the rattle, then poked at different things with a stick until the rattle stopped.

The nut holding the relay bracket was pretty tight, but I was able to give it a little more with a wrench. I'll be driving around for another week without the dash, so that should be enough to see if it's fixed or not.

The pic is the drivers side, just below the windshield. The relay is straight below the dash speaker, but you can't access it that way as parts of the dash pad are in between.

SM-S901U ?

 

The "fix" only lasted a couple days. I'm going to have to investigate further before putting the dash back together.

My current theory involves that little bit of play where the tab on the bracket(metal) goes into the body(red). When you tighten the nut, the bracket rotates clockwise as much as it can before the tab hits metal. I'm thinking it eventually vibrates back just enough to start a rattle between the two parts.

My next attempt at a fix will probably be to put something soft on both sides of the tab to see if that prevents the rattle. The other likely culprit is the interface between the bracket and the relay. I also need to check the back side of the relay to see if something is touching it back there.

 

Given where you're at, how about relaxing with a noob-level question?

I think I've got an "easy" rattle from one of the dash surface parts - the slightest pressure on it mutes it, so I fancied putting a little padding in there - but I'm stuck on how to remove it. Step 1 of dash disassembly failed.

It seems like it should be straightforward, but I've not detected any inclination to move, and I'm reluctant to apply too much force.

I was initially thinking the instructions were implying that just pulling forwards would be sufficient - but should I be doing something specific to disengage clip latches?

Any chance of a photo of this part and how it secures?

 

I am so glad you posted this because I thought people would think I was crazy if I posted. I have been dealing with this since I got my 2023 Prius AWD. It drove me absolutely nuts but I've gotten mentally used to it almost. Weirdly enough it seems to get worse when its cold??

Anyway...I am desperate also for a fix for this. I have this hunch it's part of the glove box assembly.