fuel pump noise after motor is off for few minutes normal?

[imom]

Hi,
Only recently these last few months, I noticed that when I get home and turn the motor off (key out) to my M parked inside my garage, I hear a motor noise coming from the rear near the gas tank area. It only occurs for about 30s to few minutes... just curious what that noise is and if it's common.

I did do a search on this forum, but I only read about noise while the motor is running.

Appreciate if folks let me know if this is normal or not. Thanks!

[johanness]

I don't hear a thing once she's shut down. On start-up, you may hear a fuel pump while it's pressurizes/stages, but on shut-down never heard of it 'winding down' or such. Especially not for 30secs - a FEW mins.

[ZZZZ]

doesn't sound normal to me. if it's like the e46 (someone may be able to confirm) there's a secondary air pump back there for emissions reasons that may run after the engine has shut down.

one option is of course to quickly pull the fuel pump fuse after shutting the car off ( < 30 seconds) and see if the noise stops at the exact same time.

[scottyD]

I have the same thing. It doesn't always make the sound after shutting the engine off, but frequently. It also doesn't run for the same amount of time every time I hear it. It usually ends with a "pop" sound.

It's been doing that for awhile now...I'm at 62k miles and it's been at least since 30k or 40k. Seems normal to me - hasn't caused me any problems. I'm actually glad to hear someone else out there has it too, so I'm not the only one.

I agree it's back near the fuel tank and maybe it's the fuel pump, but I haven't figured out what it is either. I couldn't find anything on these forums when I looked awhile ago. Maybe this thread will provide some info.

[imom]

I drove it around town on the freeway and back and didn't notice it... so I guess it might be something else other than fuel pump as ZZZZ mentioned.

[Endless619]

You are correct. My E46 M3 does this and so does my Z4M. Its normal as per 3 dealers in 3 different states and my private mechanic. I have heard the same noise in most of my friends M's as well. Mine is about 10 seconds or so.

[imom]

thanks Endless