I experienced the same noise as well this evening for the first and hopefully last time. However, my RX had been turned off since about 10:00 a.m. this morning. It seemed to be coming from somewhere under the rear seat console. I looked all around the vehicle and even raised the garage door to see if the buzz, which sounded like a low level generator or a distant utility line, came from outside.

I have had my 2013 RX since Sept. and have only 2k miles. My tank is about 1/4 full as indicated in a post above.

It's good to know it can be expected, but yikes looks like 2 years of it would've be resolved by Lexus by now.

Never happened to me before with any car.

Glad to have this forum. I joined quickly, too.

 

I just experienced this myself. I had filled the tank and drove a few miles home, which would put timing at just 5 five hours. I was in the garage and the buzzing started. When I kneeled by drivers rear door, I could tell it was coming from mid rear of the vehicle.

Only have 430 miles on a 2015 RX 350. I thought the same thing... Glad I found this post. I will be asking the dealership about to confirm.

Thanks for the posting!

 

There is nothing for Lexus/Toyota to resolve. This is a normal and necessary function of these vehicles. The first time I heard this was years ago when my wife and I owned a 2002 Camry. It was explained in the owner's manual just like in our RX manuals. It is to be expected and nothing is wrong.

 

Just happened to me now. Very similar reaction as everyone here. Guess instinct lead me to open the gas door and open the tank which killed the hum as built up gas escaped. Needless to say, relieved.

 

Thank goodness for this site....that buzzing sound had me crazy..I didn't dare tell my wife it was coming from her new RX350..She would have had me being it right back to Lexus and then would have been afraid to drive it again..one nite I crawled under the truck when I heard the sound and isolated it to the fuel tank area and immediately thought the fuel pump was activated.Phew!Glad to see I was wrong and that its a normal condition.I'm happy I found this site..This (non)issue should be told to purchasers by the sales people to prevent the anxieties we buyers have thinking we have a problem with our bran new vehicle........

 

It is in the very thick owner's manual - but you make a good point. This should be covered by the sales person and the delivery/technology specialist.

 

I keep my 2015 RX 350 in the garage, and last night I noticed a humming or buzzing noise coming from it. I switched the ignition to accessory position and turned it off and the noise stopped. A search here turned up many discussions noting is is the gas evaporation leakage check valve and it is a normal function of the vehicle. My question, is this some sort of pump that is running and causing battery drain?

 

It's my understanding that the unit draws very little current and is on for a short time about five hours after shut-down. No worries. It's mentioned in your owner's manual, but don't know exactly where.
Business as usual. You are now free to roam about the country.
Ray A.

 

I think it's stated on about page 23 in your manual.

 

Thanks ... don't know how I missed that out the 884 pages of the manual. (haha)

 

I let the dog out walked between both RX 350s and heard a sound like a far off house AC unit. Then found it was coming from my wife new one. I walked around that thing three times trying to figure out where the sound was coming from. While at the rear of the 350 the sound quit. I came in the house googled what I heard and bingo here was the answer. Thanks so much would have kept me up all night figuring it out.

 

A great example of what a search can find . And it's why we don't trash old threads

 

Had similar issue with my 2014 ES350. I thought I was going crazy when I walked into garage and heard this. I am going to dealer next week so I will have this verified.

 

I heard a faint sound that seemed to be coming from our 2015 RX350. I started the engine and it went away. Glad I found this thread.

 

I think I have spent a good 20 minutes leaning my ear against various surfaces in my garage trying to pin point the sound. Although I never successfully pin pointed the noise, next time I'll check under the car to confirm.