Noticed it a few months back but wasn't sure it was coming from my car. Happened again today and I managed to record it.

It started when I opened rear right door to get something, closed it and locked the car. Seems to be coming from center rear and sounds like an air compressor, but not as loud. I'm thinking fuel pump, but it kept going like this until I started the car. A few minutest at least. It almost sounds like air suspension pumping up, but IS 500 is not equipped with air suspension. Just in case, its relevant, car has very little gas in the tank right now. Showing less than 20 miles. Last time it ran was about 6 hours ago.

https://drive.google.com/file/d/16oH...ew?usp=sharing

Any idea what this could be?

 

From the owner's manual, page 5:
"Approximately five hours after the engine 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."

 

That’s the Evap system doing its routine check. Normal operation

 

This pops up randomly as you have to be there when it happens to know that it happens unless you read every page of the manual which I did not.

Welcome to the club of discovery...
https://www.clublexus.com/forums/is-...ump-whine.html

It's normal. My 2018 IS 350 did this.



I said this before... I also while parked make random sounds from the rear. This is more common after Taco Tuesdays or first thing in the morning.

 

Super impressed that you guys are aware of this. I'm not new to cars by any stretch, but I didn't know that this was even a thing. Got spooked that this was some indication of fuel pump on way out. Never occurred to me to check the manual. I guess because car is indoors, it sounds super loud, where if it was outside, I might not even notice it.

Coincidentally... I was at the dealer for an oil change earlier today. So, I emailed my advisor before I posted here. Curious, what he will say. They must get this question a lot. Plus, lots of people like myself who can't be bothered to read the manual.

 

I first noticed years ago on my 2018 IS 350 because I was near the door from my laundry room that leads to the garage and heard some sort of buzz/hum coming from within the garage. I opened the door and heard it much louder. I was able to discover quickly that it came from the backend and looked up the issue. Had I not been near the garage at the time I might not have noticed it. I've caught my IS 500 making the exact same noise, it's just a thing our cars do.

 

My service advisor replied saying that its likely the emissions self check.

Very much appreciate the replies. Thanks everyone!

 

Yep! You are not the first to notice this. Totally normal.

https://www.clublexus.com/forums/is-...l#post11846994

My IS 350 also did the same thing.

 

My BMW's are worse. Every time you open the trunk or door, you can hear the fuel pump priming along with the grille shutters moving. Sounded like something was going to eventually break. Not sure if your X3 does the same...

 

I guess I'm used to it by now. My 2016 GTI also made noises while priming its own fuel pump.