Today, after I started my car, a strange, loud groan could be heard right after I hit the power button. The best way to describe it is imagine an old windshield wiper on a dry windshield, that typical rubber on glass groan you get when it just starts. No, my wipers were off. I tried to ignore it and went on with my business. When I started up again to go home, there it was again. This time I turned the power off and restarted to hear it again. But it did not come back. All my settings in the nav sytem were reset though, luckily I had saved them in one of the user profiles. What could that sound be? It was not there before. Today was a very hot and humid day, and I've not used the car a lot recently, it sits unused for two or three days at a time. Also, it was washed recently, so maybe water got in something. Before you suggest the coolant pump: we don't have the thermos here.
Just a guess, but if the noise is a happening as you release the brake, it could be related to this TSB: http://priuschat.com/index.php?s=&show...st&p=398760
<div class='quotetop'>QUOTE(lowlander @ Jun 8 2007, 01:22 PM) [snapback]458126[/snapback]</div> I get the same thing fairly often (MY '06). I am anxiously awaiting some informative replies to your post! I'm pretty sure it's something other than the problem referenced in Post #2 above. - Doug
<div class='quotetop'>QUOTE(biphnest @ Jun 9 2007, 06:05 AM) [snapback]458507[/snapback]</div> It lasted a second or so and it was pretty loud. The brake issue mentioned here might be it, but that sound seems to occur whenever you press the brake pedal. Mine only occurs once, during a cold start, and I'm not so sure it's linked to pressing the brake pedal.
Have you ruled out the heating/cooling system? I've had similar noises in other cars when something was stuck in a vent, the noise only happens until the fan is up to speed then it stops. Also, maybe you should check your 12V battery. I'm not sure how it could cause the noise, but the heat and your not using the car much lately could contribute to trouble with that.
It's most likely the A/C ducts. I've had that noise for quite some time now. It happens when it switches to and from the recirculate vent setting. Here is a test. When you turn off your car, make sure Auto A/C is off. Then the next time you start your car, press the recirc button on the steering wheel. I bet it will make the noise when you do.
have to agree with the circulation ducts. i hear it on occasion as well. not a lot to be concerned with imm.
A bad coolant transfer pump will sound like the squeaking noise in the attached wav file. The noise occurs at cold start-up a few seconds after pushing the start button.
<div class='quotetop'>QUOTE(Marlin @ Jun 9 2007, 05:38 PM) [snapback]458663[/snapback]</div> That sounds plausible. Because of the heat, the A/C switched to recirculation right away, so it did not suck in more hot air from outside. It would also explain why it did not happen again when I restarted the car, and why it it did happen again after the first stop. Will have to experiment to see if that was it, but if the high temps caused the ducts to change shape, it might not happen again now.
I get the same thing on mine when I switch it from outside air to recirculate. I imagine there's something in there that just needs a tiny dab of grease or something. Just havn't taken the time to track it down. I imagine it's in the air assembly behind the lower glovebox on the passenger side. Probably not too hard to do. Had a quick peek in the service manuals, I think this is the area, probably around the air inlet servomotor.
Ok, I tried switching recirculation on and off, and yes, that's where the sound comes from. Incredible to see how quickly the combined experiences of other owners diagnosed the problem correctly, I doubt my dealer would have found it so quickly. I think it gets louder when the ducts are hotter, and it goes away when the A/C cools the ducts. When I find the time, I'll try to put some grease in the right spot, wherever that may be.
I'm sure I have this noise problem as well. Should be easy to fix with a bit of silicone lubricant--if I can find out where to put/spray it. Anyone know where? Thanks!
I too experienced the groan, and am thankful to this thread for helping me find the cause (switching recirculation on/off). I'm also wondering if anyone found the solution?
Nothing under the cabin filter but the motor. I have that noise too it comes and goes. It's the flap or flap motor or both. Been doing it for years.
