Just took my 06 Prius in for its 5K service, oil change and tire rotation. They also did the recall service on the steering. Since it's been back, I've noticed a faint, high-pitched noise, primarily when accelerating (gas engine, not battery) but also when braking. It sounds a little like the noise that (I think) is the battery regeneration system working, but it's more noticeable, and it's doing it when accelerating too. It almost sounded like a whistling sound the first time I revved it up to merge onto the highway, as if air was passing through some part of the engine. But I also hear it when I step on the gas during regular driving. Thought it was interference coming through the stereo speakers, but I hear it with radio on or off. It's quiet enought that with time I could probably get used to it, but it's definitely different than before the service. Any ideas? I tried searching but it either didn't like my keywords or search is broken... I manually looked through 8 or 9 pages of topics here in care/maint/troubleshooting and didn't see anything similar. Apologies if this is a FAQ, and thanks for the help.
First check the air cleaner. They may not have gotten the cover back on correctly. Then, if it were me and I couldn't find it myself I would take it back, it shouldn't be doing that. I read most of the posts here and I don't remember this problem before. This is not a FAQ, let us know what you find.
First off, please update your profile with your year, package and location. All of this information can help us when answering your questions...thanks! Sounds like the regular noise from the electric motors. Maybe because it is warmer out, you have your window down more, helping you to hear it more? When you say "gas engine not electric engine", how are you sure? They work together most of the time...thus you would hear that electric motor whine most of the time like I do. I can always hear another Prius, as they all have this same high pitched whine.
<div class='quotetop'>QUOTE(mssmith95 @ Jul 4 2006, 04:57 PM) [snapback]281105[/snapback]</div> Profile updated, thanks for the tip. I'm definitely not hearing it because of my windows being down, because my windows are up and the AC is running. It's not the electric motors, as I don't hear it when I'm in electric-only mode. I hear it more when accelerating and braking. It's not a constant noise. I also got my wife to confirm that I'm not hearing things--she hears it too. I'm taking it back to the dealer on Friday to have them check into it and I'll report back on what they find. Thanks for the replies.
Problem solved, and if I had thought about it I'd have put 2 and 2 together... After the service (which included the recall steering column thing), there were some plastic parts left on the floor of my car. I thought that maybe they were providing me with the parts that were replaced in the recall just to show they did the work. Luckily I hung on to the parts. Took it in today, let the mechanic hear the sound (he heard it) and went home. Couple hours later I got a call from Service that said "We're going to need to order some parts..." at which point I said "Do the parts look like a black cone thing and a white thing and a couple of connector rings?" Sure enough, they didn't reinstall those things (one of which is actually called a silencer designed to muffle that noise) after the recall service. The mechanic apologized and said it was the first one of those services he'd done and he just overlooked it. Apology accepted, and now I'm back to noise-free operation.
<div class='quotetop'>QUOTE(aspectratio @ Jul 7 2006, 12:46 PM) [snapback]282672[/snapback]</div> Don't you just love your car being the guinea pig.
I just purchased a 2004 Prius that appears to have this same high-pitched noise, primarily when accelerating (gas engine, not battery) but also when braking. I called the dealer and verified that the recall for the steering column had been done. I explained the noise to the service department, but they seemed clueless as to what it could be. Is there a way I could examine my steering column to see if my car is missing the parts as yours was after the recall service? Does anyone have any pictures of these parts or what the noise dampener looks like? My car has 36,500 miles on it so it just went out of warranty so I would rather not have to take it in unless I know the dealer will cover it. If the recall service was done improperly then they will likely cover the cost of fixing it, but I need some way to verify this before I take it in. Where is the dealer that serviced your car? Maybe if I contact them they could help me verify if the service was done correctly? Thanks.
<div class='quotetop'>QUOTE(aspectratio @ Jun 27 2006, 11:16 AM) [snapback]277393[/snapback]</div> I didn't know there was a steering recall on the "06.
Some very early 06's where affected by the recall. I bought mine in February and I was not part of the recall.
Ooh, I never caught the beginning of this thread but now that I see it, it explains a lot. The black cone thing must be that piece that goes around the base of the steering column as it heads into the floor, which has some white fiber padding lining the inside. Likewise, there's a large black plastic pad on the back of the transaxle / motor housing with similar white padding, on the inside toward the motors. I always wondered about the latter, and now it's pretty clear that together they're designed to muffle the sound of screaming motor windings drifting into the cabin. . Okay, so clearly it's time to go take those things *off* once the weather improves so I can actually hear the windings singing their beautiful hundred-amp canto... . _H*
<div class='quotetop'>QUOTE(hobbit @ Mar 7 2007, 10:18 PM) [snapback]401997[/snapback]</div> Thanks for the description Hobbit. I confirmed the black cone does exist on my car just before the steering shaft goes through the firewall. Not sure about the underside since I can't very easily see the underside of the vehicle. Still not sure what the root cause is of the high-pitch noise when accelerating and braking and the engine is running. I'll keep looking.