I have an 07 Prius with a little over 10k miles. I've noticed in the past few weeks that when pressing the start button on the car after it hasn't been used for a few hours, a normally sounding steady whirring noise that goes on for a few seconds (which I *think* from reading some sites online is the "warm coolant pump") now sounds different and strange. The noise has changed from a consistent, steady whirr which lasts a few seconds to something much more irregular sounding, as if it's "struggling." I realize this is very vague, but does anyone have any thoughts or suggestions about this?
If it's gotten a LOT louder it might be worth having it looked at...the pumps have been known to fail. But it sounds like it behaves when the temps get cooler...it sounds like it really struggles in the cold winters. If it's not a lot louder I think it's OK. How does it sound when you shut down and the coolant is nice and warm?
I have 2007 also and live in your area. I get a steady whirr when stopping and when starting (but not 100% of the time for some reason once in a while there is no whirr.) I think I have heard the whirr unsteady a few times. It may be just other things kicking in at the same time during the start. In any case the pump has a 15yr/150k warranty in CA.
Had the same problem with our 07. Twice. This failure is not a rare occurance. The sound is bearing failure, had heard it many times before in PC fans, especially bushing bearings, seldom from ball bearings. It started after 6 months, got progressively louder, to the point of being embarassing when getting out of the car in a parking lot and people stared. Took it to Joseph Toyota in Kent (OH) around the 1 year anniversary and the tech said it was normal, what they could hear of it. I wasn't happy, but I said no problem, I'll be back in a month, guarateed. Three weeks later and much louder they of course agreed it was out of spec and ordered a replacement. Fast forward 16 months, the replacement pump is starting to make the bearing noise again. I am livid. Just passed the 30k mile mark, glad to hear it will be under warranty when I have to replace it again in a few months. IS TOYOTA LISTENING??? Next time around I will ask to look at the pump to see if its possible to force a dry lubricant into the bearing, or if a different pump can be used that isn't a problem waiting to happen. I bought some tungsten disulfide powder for another purpose, but it would be perfect for this need. If you have that noise in your car, don't take any guff, get it replaced. If 50,000 pumps have to be replaced, hopefully something will be done about it. The question I want answered is, will the new model Prius use the same part?
No. The pump in question here is the coolant heat recovery pump, and the 2010 Prius does not have that system installed.
You didn't say you wanted this question answered too, but in case it's not just rhetorical, Toyota is listening. They issued a TSB a year ago. It will be replaced under the power train warranty (60K miles, 5 years). And next time for you, whatever design defect led to the noise presumably has been fixed; there is a different part number for the new pump.
