Grumble noise before and after gas motor runs

I have 2-Prius (Pris), an 04 and 05. Recently, when shutting down, there was an intermittent grumble noise, as if a bearing going bad in a motor turning. Now it happens just before the gas motor comes on, and also immediately after the shutting down the gas motor. It is not the coolant pump that runs 30 to 40 seconds after turning off the car. This motor is down low by the driver's side tire. And it seems to be related to the gas motor coming on or shutting off. Once the car is warm, and I shut down without the gas motor on, the grumble does not happen. ....only when gas motor first comes on from cold start, or shutting down with gas motor running, is the noise heard. My guess was maybe an gas fume evaporative motor?

Whenever I make it to the mechanic, I am on electric power in the sales lot, and the noise will not happen. His comment was that if it is driving fine, and no check engine light, then keep on driving. It is now worse, and I worry that whatever motor is failing will eventually stop and then gas motor will not come on.

If one can listen real close to this front driver side tire area when first starting a Prius, you can hear a faint motor run 4 or 5 seconds before the gas motor cuts on. And again, if you are stopping the car while the gas motor is on, you can hear it for a few seconds. What motor is this? Thanks

 

Yes. I try to put oil level in between full and low. Long ago, from people who race cars, the lower the level in the oil pan, the less friction as the crank turns and plashes through the oil.

But this grumble noise is prior to the gas motor coming on. ...as if a fuel pump building pressure before you start motor. ....only, the first I heard it was always after shutting off motor. So that would not be fuel pump. And now that it is worse, it happens when first starting up and again when shutting down. And it is always in relation to the gas motor, only happening when gas motor first comes on, and immediately when cutting off.

 

Used to only hear this grumble after shutting down and getting out of car. Now, it happens when starting also. And it is down by front driver tire. I've read about the brake bark. Mine happens without foot on brake, happening after I've gotten out of the car (and it is not the usual water pump the comes one 30 to 45 seconds after car is off).

I have 2-Prii. an 04 and an 05. It's the 05, with 65k miles recently making this grumble sound, as if a bearing is bad in an electric motor. It was intermittent when it first started. I can press the start button, jump out of car, with hood up, and put head down by front tire and hear this motor running a few seconds before the gas motor comes on. Same thing after shutdown. And, it always has to do with the gas motor, either coming on, or stopping. If I press the stop button when the gas motor is already off, the noise does not occur. I can only hear the grumble just before and just after the gas motor runs. When I go to the dealership, I am on electric power through the car lot to the back, and cannot make the noise happen for them to hear it. I guess I will have to leave the car overnight. Hoping someone on hear can give me an idea as to what to tell mechanic. Thanks

 

Thanks for the replys. I've been awawy from the computer a few days. I'm about convinced it is this coolant heat transfer pump making the grumbling bad bearing sound. Read several other threads about this. But no one seems to answer the question of wether or not it is covered under the 70k emissions federal mandated warranty. If any sensor goes out in 70k, causing check enging light, federal law requires manufacturer to fix this. I am thinking this coolant pump is part of the low emissions system on the Prius.

Anyone ever talk to the dealer, or Toyota about this pump being covered under the emissions controls warranty?

Anyone ever try to lubricate this pump?

Read all about replacing it. Not to hard. But getting all the bubbles out of the coolant when refilling seems a little involved.

 

Thanks Dan. Actually it could also be said the grumblilng noise is Me, carrying-on about the grumbling noise. Noticed the other day, my Wife's 05 is now starting to make the noise.

Going to ask Toyota if this pump is part of the emissions controls, because federal law requires these items be covered for 70k. Not many dealers tell people this. But it is in the Prius brochuer. Saw it there, not exactly sure were at the moment. And also, going to raise car up and see if any oil can be put into this motor.

 

Yep, still driving. And grumble noise is right regular now, like clock work. No more intermittent. I am still leaning towards this Coolant Heat Transfer Pump. The location is right, and it seems to go along with filling the ICE heads with warm water before starting it, and the pumping warm water into storage tank after shutdown. And yes, colder weather is louder.

Saw on one post where it is like $150 for pump, and $100 labor. I've got 68k on car. If North Carolina, or Federal is 70k on Emissions Warranty, I'll be headed to Toyota local dealer right after trip I'm currently on. Car seems to run fine. Saw also that as long as I hear noise, then pump is working. It is when noise stops that I've got bigger problem. Ha Ha

I am on Dial-Up Dead Stinking Slow at my house out in the middle of nowhere, USA. Researching threads at that speed is not happening. Maybe after 3-days at this Wi-Fi motel I will be able to figure out more.

Still Love the Pri's though.

Not to change subject too much. Ran off road one morn., jerked wheel to the point car should have skidded sideways. But lots of red lights flashed on dash, steering wheel seemed to have mind of its own, and car straightened right out. You cannot find that in too many cars, huh?