funny sounds at startup and power off

Sorry if this has been posted before...I did a search.

When I start the car cold in the morning it makes some funny sounds, like there is a weasel being electrocuted in the front left part of the engine compartment.
When I shut the car off, it sounds like there is a munchkin banshee somewhere in the back. These sounds don't last long..20 sec or less.
Any idea what these are?

Front left at startup would be the coolant pump, and anything-banshee
would probably also be the coolant pump but I can't think of anything
that sounds like that in the *back*. Are you sure it isn't the
same thing? Try all this while sticking your head out the window
and see if you can localize it better..
.
_H*

If the noise is most noticeable during a cold start-up and sounds like the noise in the attachment (listen for the noise that starts about about 9 seconds into the clip and lasts for about 6 seconds) then it's the coolant transfer pump (not to be confused with the inverter coolant pump). The noise is definitely not normal. The coolant transfer pump needs to be replaced.

<div class='quotetop'>QUOTE(hobbit @ Sep 13 2007, 10:24 PM) [snapback]512278[/snapback]</div>

I think this is happening to my car as well. I took it to the dealership but couldn't get it to make the sound again because it only happens on cold starts. How long until it "goes"? and what happens when it does? Thanks for the sound clip. That was helpful.

Munchkin banshee? As opposed to a fully developed banshee?

The car makes certain unusual sounds sometimes even when it's off, even hours after you've shut it off. It's normal (if those are the same kinds of sounds you're talking about). The owner's manual talks about that.

<div class='quotetop'>QUOTE(biphnest @ Sep 13 2007, 08:13 PM) [snapback]512306[/snapback]</div>

Thank you for that. I have a sound very similar to that, although it doesn't seem quite as loud as your example. Do you have any references (technote #, etc) on the transfer pumping needing to be replaced? I figure if you did it would help when I go to the dealer...

Mr. Zorg.

The noise was growing louder and louder over a period of several months. The recording was made with the microphone in the engine compartment.

The only technical information that I have is from my service receipt:

Cause: Hot tank converter pump noisy

Correction: Replacement pump part number TOY: 16290-21010

Description: Pump assy, Water W/M.

I mentioned "not to be confused with the inverter coolant pump" because there are two separate pumps in the same general location within the engine compartment. The mechanic first replaced the inverter coolant pump. That didn't stop the noise so he then replaced the coolant transfer pump (AKA hot tank pump). That fixed the problem.

Interestingly, there is a diagram of the coolant transfer pump on page 324 of the 2006 owner's manuals. In this diagram the pump is referred to as a "electric water pump."

<div class='quotetop'>QUOTE(timbobo3 @ Sep 14 2007, 11:36 AM) [snapback]512266[/snapback]</div>

If you leave the bonnet unlocked over night and very quietly sneek up on the car and quickly open the bonnet you are likely to see a weasel wired and ready to be electrocuted playing cards with a munchkin banshee!!!

I tell my friends that it's just the prii saying hello or goodbye..

<div class='quotetop'>QUOTE(biphnest @ Sep 13 2007, 08:13 PM) [snapback]512306[/snapback]</div>

Thank you so very much for the description and the sound clip. My Prius began making the same noise about 2 weeks ago. This makes my visit to the service department much easier.

<div class='quotetop'>QUOTE(greenwheels @ Sep 13 2007, 11:42 PM) [snapback]512319[/snapback]</div>

This is exactly what I'm experiencing with my 2007 Prius. It has about 12,000 miles. Now I know what to suggest to the service department. Thanks!

After a cold start, my car also has begun to make a noise similar to that in the .wav file. I've got 30,000 km (18,000 mi) on the car.

HI,
Could not get the wave file to play but for my reference what is the battery state on the mfd please? How many blue bars or are the bars another color? My 07 made quite a racket with pump noises I never heard before when my hybrid battery was really low at one purple bar. I hear the brake boast pump once in a while but when my batt was low heard different noises. Its a crazy car isn't it?

<div class='quotetop'>QUOTE(JayGoldstein @ Sep 15 2007, 04:28 PM) [snapback]513119[/snapback]</div>

Update: today, I noticed a loud "growling" noise also occurring right after the engine is shut off. It must be the pump which transfers coolant to and from the thermos that is starting to fail.

BTW, the noise is not in any way correlated with the charge level of the battery.

I'm not getting a noise at start-up but I do get a noise after shutting the car down - usually after a relatively short trip (<15 miles). I've been assuming that it's the 'electric water pump' that is referenced in the owners manual.
I've got <600 miles on mine - and the noise doesn't sound like the file. Am I ok to assume that it's the pump that the manual talks about?

I've owned a 2005 and 2007 Prius. The 2005 had the transfer pump start to growl at about 30,000 miles. Since I traded it in to the dealer I never had it fixed, I just mentioned it to them when I traded the car. Now my 2007's transfer pump has started growling at 13,000 miles. I had hoped they had improved the design, but clearly not. Looks like this is going to be a big issue for these cars.

Uh oh. I think I heard this noise for the first time on my car this weekend.

I will have to pay more attention in the future and see if that's what it is. Thanks for the audio file!

<div class='quotetop'>QUOTE(timbobo3 @ Sep 13 2007, 07:06 PM) [snapback]512266[/snapback]</div>

I have absolutely nothing helpful to say about this. BUT it reads like something you could have a great time on "Car Talk" with. I'm pretty sure Tom and Ray would LOVE your descriptions. AND they might even be able to help with the diagnosis!