Humming Motor Sound Coming From Under Car While Off

[F_R]

My 2010 RX350 was sitting in the garage last night, engine off for an hour or more, and I heard a small elect motor sound running under the car? It was a humming sound, a bit like water running through a pipe or a small elec motor running. I crawled under the car from the rear and could tell for sure it was coming from the car and just as I got closer it stopped. Anyone heard similar sound?

[The G Man]

That should be the gas vapor purge system, all new cars will do that. Your fuel system is seal, if the pressure builds up too gas due to off gas, the system will purge itself.

[BadBrad]

ditto....it's in the book

[LEX-SV]

My 07 IS350 has been doing this lately? I'm thinking I filled my gas tank recently, otherwise I never noticed it before. I'll check with the 2nd gen IS owners to see if other experienced this.

[KingBiscuit2112]

That's happening to mine now. 4 months left on the warranty. Last time was on an Acura TSL, it was suspension related. I have a "sound" up front too so I'll be dropping it off soon anyway... They will damn sure check it! The recently part doesn't sound right.

On ‎9‎/‎25‎/‎2013 at 7:03 PM, LEX-SV said:

My 07 IS350 has been doing this lately? I'm thinking I filled my gas tank recently, otherwise I never noticed it before. I'll check with the 2nd gen IS owners to see if other experienced this.

 

[Puzzled in AZ]

Well at least I’m not alone. Our 2016 RX350 has this sound coming from the rear of the car after it has sat in the garage for three to four hours after it has been operated. At first I thought it was the hatch motor. But cycling the hatch didn’t remedy the noise. I had to start the engine for a minute or two and then shut it off for the humming noise to stop. It’s not a frequent issue I don’t think, but it concerns me that it is still doing it. Does anyone have a technical explanation for this phenomenon? I’d rather have some back up from other owners before trying to explain this to our service tech.