Just got mine fixed...very difficult find. It took about 30-40 hours to find almost lost my mind. I was sure it was coming from right side of dash...maybe around the speaker area or side window vent. I took most of the side dash pieces out, glove box air vent speaker grill no luck...pulled the inner fender well out and the inner door plastic out I found it to be the tip of the front fender where it meets the roof viberatiing...you can confirm yours by tapping about 3 to 4 inches forward of the outside mirror...that part of the fender is unsupported. I put to felt pads when 3m tape wrapped around them pushed them up between the inner fender and gone...I took some pics but am new to the board and felt I owed it to you guys to post my find...Toyota shop said they would have never found it...I showed them
Try tapping 3" or 4" forward of the small triangle window on the outside of the fender. When you get it apart look all the way up you will see what looks like 2 pieces of metal that are very close to each other put your make shift brace between them. If you pull the clips from fender well pull clips from center. I had to replace some because I did not understand how they came apart...cheap to purchase. I hope this can get out to more people...
How much do you need to disassemble to get this done? pics? I don't have any rattles, but this sounds like a design flaw that would be good to address in advance.
I am just jaw-dropping amazed at how quick some of y'all are to disassemble your new Prius for a rattle. I think this same rattle could have been corrected from underneath the car by accessing through the rabbit holes that run under the front windshield toward the side fenders. Someone posted that they stuffed rags into those holes and it took care of the problem without having to disassemble. I think I have this rattle also, but I find that it's harmonic with the engine RPM at lower speeds; i.e. not constant. For me, to make the rattle quiet down, I let up on the accelerator ever so slightly. Congrats on a rattle repair well done, but I'm not that adventuresome!
twittel...this is the very rattle I am discussing...mine was just as you describe. I think it is a design flaw. It can be fixed in less than a half hour with no harm done to anything if you are carefull...worst case a few new clips. It really drove me nuts on long smooth straight roads...once the ear is trained on it...hard to get over it. I will try the upload thing soon.
You just zero'd in on my problem: I'm not patient enough to be careful! I'll look for the upload; thanks.
Just a small note on the find...you do not have to remove the whole inner fender start at the bottom bolt then move to the clips pull the inner fender aside so you can look up with a flash light...you should see the area at the very top just forward of the triangular window.
That was me. It took me weeks to finally discover the cause. I don't think this design flaw is a frame weakness. Toyota could have plugged the "rabbit hole" with some insulating foam to prevent the noise transfer from the engine compartment. Stuffed rags did a nice job for me and there's no fender removal either. Another concern is that engine fumes could directly enter the cabin as the culprit A frame on the interior has large holes perforating it (at least 1/4 inch diameter). You would have to remove the passenger A frame garnish cover to see this. One member here wanted to inject expanding foam in the rabbit hole to solve this noise, but if the foam expanded under the garnish cover (Toyota's term), it could impede the safe deployment of the side curtain air bag. The rag method is fast and easy and I see no danger of water wicking into it if it is embedded high enough out of the way of the rain water discharge path.
Re: Dash Rattle - Different Cause dryrider, I too had the passenger dashboard rattle, sporadic, unpredictable, but generally linked to a specific engne RPM, not sure exactly what the RPM is. Looked a lot of things, like yourself, followed other tip about stuffing rags, which did reduce overall noise, but not this specific buzzle (cross between buzz and rattle). I began to notice the buzzle was not only related to engin RPM, but also vehicle speed, never hear it less than 15 MPH and never hear it over 45, perhaps road noise just washes it out. Saturday in the big wind I noticed that on the same street, in a big crosswind, the noise was bad when driving in one direction, not gone when driving the other way. I tapped around as you suggersted and indeed the fender is very unsupported right under the small front window, in front of the mirror. I noticed that there was a lot of flexing of the sheet metal, right under the weather stripping on the lower molding of the small window. Just for grins, I slipped a business card in between the sheet metal and the lower window molding of the small side window, and bingo, buzzle is gone! The card sticks out about 3/8" and it is positioned as far foward as possible, even turning upward around the corner. I been driving it for several days with no buzzle, quite happy. I believe the buzzle is caused by a combination of speed sensitive aerodynamic effects changing the clearance between the metal and vinyl, combined with some resonant frequency from the engine. The entire fender area is very flexible and the car itself seems pretty tightly coupled to engine vibration. The car looks a little funny with a very thin fin sticking out of the right fender, and I am really not sure how to put in place a durable fix. I could try and explain this to the dealer, but that could be a disaster. I could try and add some silicone or flexible sealant, but that could also be a disaster. I could try to contact Toyota but that would probably end up in no fix at all, as I imagine they would not even acknowledge that there could be a problem like this. Not really sure how to proceed, but in the meantime, I am not distracted by the buzzling noise.
Why? It's peoples cars. They own them. I'm impressed, sometimes astonished at a lot of things people do to their new cars. Hang around automotive forums to any degree and you will be further amazed at simply the elective modifications people choose to make to their vehicles. To me if you have a rattle? You can decide it doesn't bother you, isn't worth trying to fix or track down, or you can decide it does bother you and spend whatever amount of time and effort to track it down. If this is a common rattle, I'd hope these pictures get forwarded to Toyota so they could "modify" how the bumper assemby is attached. Then owners wouldn't "have" to try to fix it themselves. Sounds to me like once discovered, a realitively easy fix. Something that could be adressed in production probably pretty cheaply and easily.
