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.
That sounds like your ABS accumulator pump is working over time. Does it make that same noise if you pump the brakes four or five times in a row?
x2 to dolj While it's not uncommon to have the pump for the coolant heat storage tank get noisy, it's usually more of a "squawl" that happens for a few seconds after you go "ready". (It's a little pump with plastic pieces inside). It also runs a few seconds after shutdown. Yours sounds a lot more "heavy" and "metallic". (I thought you had an air compressor running in the background). The brake system pump will switch on when you open the door - before powering on. Then back on as you use the brakes and deplete system pressure. Posted via the PriusChat mobile app.
