My 2017 Prius Two hybrid fan battery just started making this noise: Dropbox - FAN.m4a I was holding my phone fairly close to the fan when I recorded it so it’s not quite this loud from the driver’s seat. It used just be a nice soothing “fan” sound, this sound is part high pitch and part rattle. I have about 40k miles on the car. The sound starts at any speed above 35 mph and then stops when the speed drops below 35 mph. Any ideas?
I couldn't get your sound link to work. Does your dog ride in the Prius with you? Any chance the hybrid battery vent is dirty? In the 3 years I've had my Prius, I don't believe I have ever heard that fan come on. I always drive with the AC on, and set to high/low vent. Maybe that helps cool the battery? I also hold a vacuum hose up to that vent once a month. It's definitely worth going to the dealer and getting your fan/vent checked out. It's odd that it stops below 35 mph.
Hmm, I wonder why the link isn’t working. Yes there’s lots of dog hair in my car. I’ve cleaned the vent and filter out once before and I was going to open it to take a look at it in the morning. It’s been dirty before but didn’t make the sound it’s making now though. My battery fan has always gone on pretty frequently, mostly when it’s hot outside.
The link says I need to create an account, and/or install an App? Then I skipped the App install, and it says the address is invalid/can't play. Anyway, I'm sure the experts will chime in here and diagnose your fan problem. Now I'm wondering if mine even works? Never heard it, even when the car is quiet. (Low speed/radio off.) @MendelLeisk put a little screen over his vent opening to catch the hair? I wish I could say she's mine. This is my sister's girl.
**UPDATE** So the vent cover and filter were COMPLETLEY covered with husky hair and the fan was full of dust. I cleaned everything out and now it’s quiet again. I put my hand over the vent while I was driving and I felt air being sucked in so it seems that it’s bringing air in even if the fan is not running. I think that’s why I was hearing the sound above 35 mph because the faster you drive the more air is going in. I don’t know if the fan is running all the time but I do hear the fan get louder at times when it’s hot outside.
I put my hand over the vent while driving, and I can't feel any air being sucked in. (I also can't feel any AC air coming out of the vents under the seats.) My Prius is a mystery. Trying to figure out how to pry open the vent grill so I can take a look in there.
Link worked fine for me. It sounds like the common rattle sound you hear when the spindle or blade assembly on a brushless fan (like the ones in computers and laptops) get loose and eventually fail. As your vehicle is still under warranty, take it to your nearest Toyota dealer to get it replaced for free. It will fail soon, and that risks an overheated battery.
You just take off the little plug with a Phillips head screw driver and then the vent just snaps off.
So I drove around for an hour, leaning over to the right with my hand on the vent grill. (gotta have long arms.) I finally felt some air down there, didn't hear it, but felt a little breeze. Felt like it was being blown out, rather than sucked in. Whatever, at least I know something is working.
I just tried for 15 minutes trying to get that little plastic screw out of the fan grille. Turn it one way for five or 10 minutes, turn it the other way for a few minutes. It won't budge. It just spins. Then I tried prying it out of there with a flat screwdriver. And I knew I would break it, so I stopped. Everything has to be difficult with this little Disneyland car! I guess the hairy mountain lion will have to stay home and can't ride with me.
So it’s not really a screw, it’s more like a pin. You have to use a small flat head screwdriver or your fingernail and gently pull on the center pin while you’re turning it counterclockwise with a Phillips head screw driver. It will come out that way. Then once the pin is out you can pull out the outer ring.
No dice. That thing is glued in there! I pried, picked, poked, pulled.... and cussed! The screw won't pop out, and I put a thin butter knife blade in the seams around the grill, but its in there solid. I'll just leave it, for now. Thanks.
Hmm. You should be able to get a blade or something very thin between the center pin and the outer ring and gently pry it up while you’re turning counterclockwise with a phillips head screwdriver.