[G550guy]

I just went out in garage and there was an electric motor noise coming from under rear of my CT. Car hadnet been driven in 4 hr or so. Wondering if anyone knows what it is?

 

[evicfinite]

yea your car is going to explode.. you better toss some ice on it!

 

[dkid]

I just went out in garage and there was an electric motor noise coming from under rear of my CT. Car hadnet been driven in 4 hr or so. Wondering if anyone knows what it is?

It is normal. Probably cooling the battery. Our cars make lots on noises for a long time after they are driven. They will start making noise when you walk up to them and open the door.

 

[jeffp]

the same thing happened to ours yesterday. like yours, the car had not been driven for about 4 hours. anyone else notice this?

 

[G550guy]

yea your car is going to explode.. you better toss some ice on it!

Thanks DB, that was helpful

 

[Dirvin]

4 hours seems a bit excessive. It seems like the battery would have been cooled off long before. It will be interesting to see how many others are seeing this as well.

 

[jeffp]

I might have found the answer. A thread from a Prius forum mentions the sound I heard. The best answer I could find reads as follows:

On page-22 of owner's manual, it says...

Noise from under vehicle after turning off the hybrid system
"Approximately five hours after the hybrid system is turned off, you may hear sound coming from under the vehicle for several minutes. This is the sound of a fuel evaporation leakage check and, it does not indicate a malfunction."

 

[G550guy]

nice- thanks, i'm sure that is what i heard

 

[coubs]

I have read on this forum about the "evaporation leak check" and I think there is something else in that it circulates the coolant so that if you restart your car it is warm(er)? Lots of interesting technology that's for sure.

 

[Beezbreezy]

speaking of noises... has anyone gotten a "cold start rattle" or a knock during start of engine?

 

[Sleepypete]

I have read on this forum about the "evaporation leak check" and I think there is something else in that it circulates the coolant so that if you restart your car it is warm(er)? Lots of interesting technology that's for sure.

I think there's 2 systems at work :

First is an exhaust heater system that uses a heat exchanger in the exhaust system to heat up the coolant faster when the engine is cold. When the engine is warm, the heat exchanger is bypassed. I think that's partly what you mean there

Second is a vacuum bottle which stores hot coolant for use later. Wiki for the Prius says US & Canada only so this might not be on my UK CT. Although it could explain the whirry noise when you get close to the car for the first time in a while - it could be taking the hot coolant out of the vacuum storage and warming the engine up a bit.

Dunno about the detail though. The "evaporation leak check" is probably working on either the vacuum bottle or the aircon.

 

[rehabmax]

You could make a Sci-fi movie with the sounds this car make in the garage at night. I have had the CT200h for 7 months and every night around 11PM it starts doing its nightly electronic musical. Usually i get home at 6PM so this doesn't begin for a good 5 hours after the car is off. I don't know if it some computer run through or hybrid battery thing. I would like to know what the car is doing up late at night when it should be asleep.

 

[jimmyc13]

Wow, never knew the car did this, nor have I witnessed it. Crazy that 4-5 hrs. after you shut the car down, it's really just taking a snooze and comes back to life by itself to do this! Kind of cool.

 

[bumski667]

speaking of noises... has anyone gotten a "cold start rattle" or a knock during start of engine?

I think i experienced this issue this morning. I started, and heard knocking, or what sounded like a fan spinning hitting something. As soon as I depressed the accelerator, it went away. Any ideas? I was going to take it to the dealer, but not sure if I can replicated it. First time happening this morning. 20k miles.

 

[CTDEMO]

It's alive......my CT also makes some strange noise (small motor running sound) at night........creepy.....

 

[Dom]

Yes has happened at least 3 times in the last 9 months would like to know what that is.

 

[ncaaaddict]

Yes, my CT just did it a week ago on a cold morning sitting outside in the driveway overnight. I have just about 20,000 miles on it like you. I am interested on what your dealer told you the problem was. I'm probably going to have to take my car in for them to inspect, but don't know if they will be able to duplicate the conditions. Thx

 

[NTO]

I heard the same noise last night and again tonight. Glad to know I'm not the only one!

 

[TSoprano]

You could make a Sci-fi movie with the sounds this car make in the garage at night. I have had the CT200h for 7 months and every night around 11PM it starts doing its nightly electronic musical. Usually i get home at 6PM so this doesn't begin for a good 5 hours after the car is off. I don't know if it some computer run through or hybrid battery thing. I would like to know what the car is doing up late at night when it should be asleep.

it's dreaming because it has a very unique A.I. controller for the hybrid system..

 

[ruffino28]

I just went out in garage and there was an electric motor noise coming from under rear of my CT. Car hadnet been driven in 4 hr or so. Wondering if anyone knows what it is?

I got pretty much the same problem, but 7 hours not 4