I suspect my six-year-old stuck a small paper wrapper in the battery vent of my new 2010 Prius. A few days after the deed I noticed the fan making a fluttering noise; sort of like an old computer fan. The sound gets worse at high speeds. A passenger thought it sounded like an insect chirping. Until that point I had never heard the fan come on at all (after driving two months in hot weather). The Toyota dealer took a look but initially couldn't reproduce the sound. After some prodding and testing, they agreed there was an issue. The guy said he'd order a new "blower" but that if they found cause to be something thrown into the vent, I'd be responsible for the cleaning costs - probably two or three hours of labor. My wife (who hasn't heard the noise) thinks I should just live with it. Yeah, I suppose I could but I'm also worried it might not be cooling the battery pack as designed. I'm wondering if anyone else has had a similar experience or can offer a cheaper way to fix the problem. Thanks.
Check the cabin filter, see if you find any nuts that made it through the filter. My cabin filter trapped a lot of crap
I'm not sure what Cossie was talking about, because we're talking about the battery fan. The cabin air filter is the air conditioning filter located behind the glove compartment. Let us know the outcome of replacing the "blower". How many miles are on the car? Reason I ask, is because I've seen other threads similar to yours (in the Gen II) with their fans coated in animal hair, dust, and grime. If this IS the problem, then you may want to cut out a filter to place behind the grill of the fan intake. I know this is a pretty vague post - however the verdict is that there may be debris in the fan, or the fan simply needs to be replaced. I assume when they replace the old fan, they'll tell you if it had all sorts of crap in it or not. Good luck!
The plastic casing just pops off and you can get to the fan pretty easily. Pull out the offending trash, and it will be as good as new.
The casing pops off? How is it attached? Any images or basic instructions for this procedure? I'm mechanically inept and would hate to damage something.
Do you know someone who is good at things like this, that would be the easiest way to get it fixed. I had to get to my battery fan on my 04 prius, part of my improvised filter got sucked into it, I was able to stop before the battery (or fan) was damaged. Remove all the stuff in the hatch area, remove the (rear) vent cover, a few nuts to remove for the rear panel, a few odd plastic retainers to remove, just tug away and observe what happens. I did have to tug fairly hard on the plastic vent pieces around the fan to remove the fan (which in the 04 is held on by three nuts). I do probably care less about the condition of my car than the average prius owner,which gave me some confidence in taking this task on . High mileage, work car- no longer 'pristine'. Also, do all this when car is 'off' , forget to initially mention this.