Noise from Rear When Car Parked
 

Hello Forum, I tried searching to see if anyone has had a similar experience but didn't think anyone has mentioned this situation. I have a 2013 TCH. I'm fairly handy with cars so I wouldn't post here if I thought the noise was normal. However, I am new to hybrids. I understand that when you walk up to the car the car activates a pump that I believe operates the parking brake. I've heard this noise all the time and understand it's functioning normally as I walk up to the car. The noise that worries me sounded similar, but was coming from the rear of the car, somewhere between the two rear wheels. I understand this is where the battery is. Let me explain the events before the noise occurred. I don't like to, because the car is new, but had to drive to an appointment while it was snowing. The roads were slushy but not covered in inches of snow. I'm pointing this out because I wasn't driving in a foot of snow or something where the snow was possibly jammed up into the rear of the car. It was all slush, water and salt less than 4 inches. I drove to my appointment - about a 20 minute drive. Stayed for 4 hours, then drove back to my house - 20 minutes. Everything appeared normal as I parked in the garage. No unusual sounds. Shut the garage door - went inside. No one home but me. About 3 hours later, I took some trash to the garage and heard what sounded like a small electric motor. I quickly narrowed down origin of the sound to the rear of the car - somewhere between the two rear wheels. I would have got under the car, but the snow and slush made the ground wet and I didn't want to get all wet. So I opened the car door to see if I would hear the usual noise of the parking brake hydraulic pump or whatever it is. Yes, this came on and sounded normal but came from the front of the car. It turned off and the sound from the rear kept going. I turned the car on...in EV mode and then turned the car off. The sound from the rear stopped. What worries me is I'm thinking something may have became wet under the rear and was running a little motor or caused something to goof. Has anyone else experience this? Is this normal? Does the car have to maintain the battery at times or something in the cold? Thanks for your help. I think I will take the car in soon just to have it checked.

Re: Noise from Rear When Car Parked
 

I inserted paragraphs so it would be easier to read...but I guess the website condensed it.

Re: Noise from Rear When Car Parked
 

Hit enter twice to create a paragraph depending on the browser.

If you are getting strange noises from your rear end, I would suggest laying off the chili and beans for a few weeks and see if it disappears......

On a more serious note, what you are hearing is more than likely the fan system on the hybrid battery or, believe it or not, the rear cabin fan. That fan tries to balance the temps between the cabin and the trunk area and the battery fan will try to keep the batteries as warm as possible (even with the car off) to help the car be as efficient as possible.

Just be aware that your new hybrid is not an ordinary car and you will be noticing a LOT of new noises and mechanical happenings both while running and stopped.

Re: Noise from Rear When Car Parked
 

Thanks for the information on creating paragraphs. I will try hitting enter twice with this reply.


Since my wife cooks most of the time, I blame those noises on her.


The soft whirl noise I heard would fit the characteristics of a fan. Thanks for your reply. That's an interesting engineering feature and makes sense.

Re: Noise from Rear When Car Parked
 

My vote is that what you're hearing is the purging of the carbon canister. A small fan runs approximately 5 hours after the HSD has been turned off to accomplish this. (Are you sure it was only 3 hours?)

The noise you hear when you open the driver's door in the morning is another pump which re-pressurizes the pressure vessel which allows the power brakes to work. BTW, this is the same part which has developed a reputation for failing prematurely on prior generation TCHs.

Re: Noise from Rear When Car Parked
 

It actually was about 5 hours later. I realized this after my post but didn't think 2 hours mattered. It was several hours after it was driven. But this is interesting and very good information to know. I appreciate your post.


I hope they fixed this failing pump on the 2012 and forward generations.

Re: Noise from Rear When Car Parked
 

I will point out after parking your car in the garage to be sure you press the power button usually once, till the dash lights go out. The clock on the dash should also go out as it's easier to see during the daytime. This would be when your park to get out to go shopping or when your home for the night. I used this method when I had the '07 TCH.

I now have a '13 TCH we park under a carport for the night. Were not around it after parking it enough to know if it makes any noises after it's parked or not. One thing for sure it rides good and we really enjoy driving the TCH.

Re: Noise from Rear When Car Parked
 

Yea I make sure to hit the power button before stepping out. I always want to see what the MPG tells me I did for the trip :D