Whiurr From The Rear.

[ukrkoz]

We own 2011 RX350. Still under factory warranty. Wife parks it overnight outside, as she's ICU night shifts nurse, so I am concernd.

This is why.

I walked into garage and heard whirring noise. Like a relay buzz or something. Checked outside - no, not from there.

Walked around cars parked inside and determined that whirr is coming from under the RX rear end.

Well, my wild guess is, it's fuel pump, but why would it be working on a vehicle parked for 4 hrs by then? Whirr stopped, I just checked, but I have no idea how long that something was working. All doors were shut, only security light blinking.

My concern is, she still has 3 nights in a row and if something electrical keeps running in the rear, battery may die.

Is it something that vehicle is actually supposed to do? Was clearly coming from fuel tank area, I had my head under the body. It's not a hybrid, so there is no cooling fans and such in the rear. My Camry Hybrid does all kinds of noises, I am used to that, buit not this. Shouldn't be making any whirrs.

Any ideas? Can't take to dealer unti Saturday.

Thank you

[pj8708]

Hi Ukrkoz,

I'm not an expert on just about anything, but I think you may be on the right track. As you know, the fuel pump is mounted in the gas tank where the gasoline keeps the pump cooled. I have heard of other members hearing sounds when the pump is going out.

In my opinion, your concern about having the battery run down is valid. A few years ago, I left the over head dome light on over night and in the morning the battery was dead as a door nail. I could not believe that a tiny light bulb could drain a powerful battery.

Paul

(My wife has 30 years as a RN. I know how you feel.)

[ukrkoz]

I actually feel fine. It helps to have her out several nights a week. :whistles:

I'll send request to Lexus support. Unless pump is supposed to prime the fuel pressure to keep it at a certain level, it should be not working. I ma pretty positive that was pump, nothing else there to make that noise.

I am more curious if someone else encountered this situation - pump working on vehicle that is completely turned off and several hrs parked.

[ukrkoz]

OK< have ticket opened with Lexus. I just had a thought. Maybe it's EVAP purge? EVAP canister should be about there too, usually they are by fuel tank filler neck.

Missed live chat with lexus, that would have been fun.

I'll keep posted.

[ukrkoz]

Oh, she just took off for work. Car started fine. Noise was for at least 5 minutes, while I was investigating, but then it stopped and I walked through garage many times after, there was none.

[ukrkoz]

So no, apparently there is nothing that is supposed to whirr in the back. Nothing pretty much obvious for a CSR online.

I apologize for any inconvenience this may have caused you and for
the experience you are having with your vehicle. Unfortunately, being
that I can't diagnose your vehicle over email and provide you any
suggestions, we do advise that you please have your vehicle inspected by
your nearest Lexus dealership.

[ukrkoz]

I'll call dealer today.

[pj8708]

Let us know what you find out.....

Paul

[ukrkoz]

Unfathomed ignorance from Lexus support. She could have Googled it. So could I, actually.

On page 22 on the (2011 RX350) owner's manual, there's a section titled "Noise from under vehicle after turning off the engine." It says, "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."

Read more: http://www.clublexus.com/forums/rx-3rd-gen-2010-2015/554691-buzzing-sound-when-engine-is-off.html#ixzz3m2k3f1Sk