2013 Gen 3 32K miles: My late mother came up with crazy theories about what might be wrong with cars. Somehow, she was always right. Now my wife swears that the rattles, first on the passenger side, seemingly in the dash, and now on the driver's side, seemingly in the dash, were being caused by the windshield wipers. I thought this was complete nonsense, but to placate her I fiddled with the wipers. The little plastic locking clip on the driver's side was loose on one side so I clicked it in place. The noise vanished. Stayed away for weeks. But on a recent trip, on some rough roads, the driver's side rattle began to return, not as bad as it had been. Stopping by the road I checked that clip. It was firmly seated. But jiggling the base of the wiper arm while it was extended caused a noise inside the car similar to the one caused by hitting a bump. I'm now convinced that she might be on to something. Anyone have any experience like this or any hint as to what I might do to pursue this theory. Could it be something with the motor or arm mounts or the connecting pieces? If so, how would I access them?
Welcome to your first post on Prius Chat . I’ve found that below the plastic cowling there are 2 collapsible doors that if not locked in position, will rattle. These doors are used to channel air through the screen and into the cabin. Might be worth checking those as well.
There's a video by @NutzAboutBolts , pinned at top of 3rd gen maintenance forum, ostensibly about spark plug change, but for the most part the journey to get there. It shows step-by-step how to remove the wipers, motors and the cowl, if it comes to that.
If you were to take the windshield wipers off and then remove the cover, you’d find the folding air channeling doors.
I just took my cowl off because I had an intermittent “plastic banging” rattle whenever I’d go over bumps in the road. See link to my original problem: Rattle in dash behind steering wheel? | PriusChat I was expecting to find an acorn or something, but I only found a fluffy rodent nest. I vacuumed it out. I also found that my middle air channel flap was down… I gave it a few good vibrations and it made a similar noise to what I’m hearing in the cabin. I noticed that the clip to hold it in place was somewhat smushed, so I couldn’t rely on it to stay put. I used a screwdriver to hold it into my preferred unsmushed position, and a hot air gun to soften the plastic. Once I had it in the correct shape, I cooled it down to solidify the plastic so it would stay in this shape. It clicked in nicely. Gave the windshield a nice cleaning and reinstalled my wiper arms. Will update if this was the solution…
