It's a 2008 with 225K. The car is making a grinding noise briefly when you first hit the on button. Is this the inverter control valve failing? There is no codes. I have changed the inverter coolant, bleed it and pump seems to be operating correctly. https://youtube.com/shorts/s9qVqqwQWFk?si=sFdnWXrxin0iH3UY Also, with the car powered on there is this humming noise: https://youtube.com/shorts/SR855n5d5Gc?si=HgK4owCeatYnTA_O
Probably the ICE coolant being injected back into the engine from the thermos bottle. It does this to decrease the time before the engine reaches operating temperature. A similar noise is heard when you shut off the vehicle as the bottle is loaded.
The first noise is the sound of the brake pressure pump, pumping you up some brake pressure you can have on tap when stopping the car. It's doing what it's there for, which should make you smile. Edit: or as AzWxGuy suggested, the pump moving coolant out of the thermos, though if it's that the recording makes it sound noisier than I'm used to. I was hearing the kind of joy-buzzery sound I associate more with the brake pressure pump. But the timing—seemingly after going READY—does sound more like the thermos pump, as the brake pump usually tries to get a head start on things by running as soon as you open the driver's door. The second noise is also normal, if you mean that sort of whiny B-above-middle-C-ish noise. You can read about it in this post.
I retract my guess. My 2008 was a long time ago. There is a noise after shutting off the engine though, as the ICE coolant thermos bottle is loaded.
Thanks for the responses. I found info on the brake pump and that seems operating normal. Is the thermos pump the same at the coolant control valve? (located under the inverter). I get the concept, it seems a bit loud but I'm not sure or if that is even a symptom of failure.
No, the thermos pump is a pump, and the valve is a valve. They are related; the valve changes positions to change the coolant flow path between normal engine operation, saving hot coolant in the thermos, or getting it out. The pumping of the coolant is done by the pump.
The first one is the thermos pump. It is physically located just above the fender liner on the front driver's side. It is a noisy pump and mine has sound just about like that for 6 years. Not a problem. The second one sounds like it might be a noisy inverter pump. If you pull the AM2 fuse it will disable the pump, but also the car won't start. There is a plug that can be disconnected to disable the pump (handy to get back on the road if the pump shorts out and blows the AM2, just drive slow and preferably not on a hot day):
Thanks again for the responses. Good to know about the inverter pump. I did put a stethoscope on the inverter pump seemed it was running quietly. So, the thermos pump is just to provide preheated coolant to the ICE to reduce startup emissions? And not something that would potentially leave one on the side of the road with a failure?
If you have the stethoscope, try also touching the throttle body with it; I think you'll then be sure what the whiny B-above-middle-C noise is. It's normal. Sometimes it happens that different people listen to your recording and focus on different sounds. The throttle body whine was the one I noticed (in the second recording), but that doesn't have to mean it's the one you're wondering about.
The thermos was an idea that didn't really pan out. It made a mess of the ICE cooling loop but didn't help very much with fuel savings.Toyota eliminated it when the 3rd generation came out in 2010 year. A thermos bottle failure is basically unheard of outside of collisions. The 3 way valves can and do go bad. But since that whole section of the cooling loop is not strictly necessary for operation the car will still keep going. There will be a code though once the valve fully fails. In CA and some other states the car won't pass smog with a code set, so when smog check/registration time comes around we have to fix this if it is broken. Could be the same in OR.
That really sounds like something spinning to me. There really aren't that many things it could be: 1. inverter pump 2. thermos pump (if stuck on, but it doesn't normally sound like that) 3. heater core pump (located behind the inverter on the firewall - I think) 4. belt driven water pump 5. cabin fan 6. A/C compressor 7. ABS unit The heater core pump is only on in certain situations. First the heat must be on and the cabin at a temperature that warrants putting coolant through the heater core. Second the ICE motor is off. Mostly it is there so that if the car is stopped on a cold day, like at a long light, and the ICE shuts off, there will still be coolant moving to keep the cabin warm. Similarly, the A/C compressor should only be going when the A/C "button" on the climate control is lit. If that was the cabin fan it would go away when the fan was off and change tone with different fan speeds. I didn't hear the ICE going so we can rule out (4). Similarly, other things closely associated with the ICE won't be making any noise when it isn't running, even if they are screaming loud when it is. So that rules out the oil pump, cams, bearings, and so forth. Also everything in the transaxle that moves. I suppose it is possible for the transaxle to hum while not moving parts if current is going into it, in the same way that some transformers hum. The ABS unit does have a pump in it, and it is located under/behind the inverter. That isn't the sound I have heard posted before, but cannot rule out some failure mode where it makes the sound you hear. Can the inverter hum? It doesn't normally, but I can imagine ways that the electronics could make that sort of noise. The DC-DC converter must have a coil or transformer in the circuit, and that could vibrate when active.
