Hello everyone, lately my 2007 prius has been making a loud noise that comes from my coolant heat storage tank. It’s more than the usual sound. it occurs when the car is first turned on and then again when it’s turned off. There are no other symptoms such as check engine light, overheating or low coolant. I have posted a link to the video. please let me know what you guys think.
That sounds like a bad electric motor of some sort. Given the time it occurs, probably either the 3 way valve or the little electric pump under the thermos bottle. You could unplug one then the other to see which. That will likely throw a code for at least the valve, but shouldn't hurt anything. To get to that pump release the front of the fender liner which extends to the bumper cover and fold it down. I think you can reach the plug for the 3 way valve once the tray is off, but I'm not positive, it has been a while since we changed ours. If you can't get to it from the top maybe it can be reached through that same flap opening.
