I'm hoping this is a quick question. In my 2015 Lexus RX there is a electric hum (sounds like a small motor) coming from the back of the car when the car is not running. It's loudest underneath of the car and it's not all the time but we've caught it doing it twice in the last week, it does eventually go off. A google search came up with a person that had a similar concern on a 4runner and the responses were that it was the fuel vapor system and that it was normal. I've had this car for over 5 years and this is the first time I've heard this and caught it twice in a week. Can someone tell me if this is in fact normal? If it is normal, can these systems go bad and cause them to run more often than necessary? Thanks.
Sounds like an evap issue, any check engine light.
No check engine light
I would try and get underneath when you can get it to happen and see if you can feel it to be more specific? Does the car have air ride? A lot of times the pumps for those can get noisy over time
I'll see if I can pinpoint it if it happens again but I did lay down and get in there as far as I could without the car being jacked up. Seemed like it was coming from the fuel tank area, my thought was fuel pump maybe going bad then read that thing online about the fuel vapor system on the 4runner and that being normal. Doesn't sound like this is a common occurrence regardless. No air suspension or anything fancy that I know of in the back of a base 2015 RX350 AWD.