Strange noise coming from behind drivers seat

[chaz_]

Strange knocking noise coming from behind the drivers seat on my 2013 E89 Z4 35i. I just noticed the noise when driving to work this morning and heard it again on the way back, seems to be coming from behind the drivers seat, maybe something to do with the fuel system as the filler cap is behind on the drivers side, doesn’t seem to be coming from the engine as I opened the bonnet and everything sounded fine, can only hear it inside the car behind the seat. Any thoughts?
I have a video where you can hear it but not sure how to upload it here?

 

[B21]

Strange knocking noise coming from behind the drivers seat on my 2013 E89 Z4 35i. I just noticed the noise when driving to work this morning and heard it again on the way back, seems to be coming from behind the drivers seat, maybe something to do with the fuel system as the filler cap is behind on the drivers side, doesn’t seem to be coming from the engine as I opened the bonnet and everything sounded fine, can only hear it inside the car behind the seat. Any thoughts?
I have a video where you can hear it but not sure how to upload it here?

You need to load it to YouTube then post the link here…


Comme Ca

https://youtu.be/WzKaOmHrhrQ?si=MjVMOWpyDApryD7G

 

[chaz_]

Alright thank you. Hows this:
https://youtube.com/shorts/lt3lF_uXdZ4?si=BNzbSzDgUw6RHpD8

 

[B21]

Alright thank you. Hows this:
https://youtube.com/shorts/lt3lF_uXdZ4?si=BNzbSzDgUw6RHpD8

So is there any sounds with ignition on but no engine running ?

Does any sound like that appear on initially opening the door?

What engine is it ?

 

[chaz_]

Alright thank you. Hows this:
https://youtube.com/shorts/lt3lF_uXdZ4?si=BNzbSzDgUw6RHpD8

So is there any sounds with ignition on but no engine running ?

Does any sound like that appear on initially opening the door?

What engine is it ?

Thats a good shout, I’ll check if it makes any sound with the just ignition in the morning. The sound is so faint that I can only hear it with the door closed, when I walked around the car I can’t hear anything, no unusual sounds from the engine bay either. It’s an N54 engine, 35i model.

 

[B21]

Alright thank you. Hows this:
https://youtube.com/shorts/lt3lF_uXdZ4?si=BNzbSzDgUw6RHpD8

So is there any sounds with ignition on but no engine running ?

Does any sound like that appear on initially opening the door?

What engine is it ?

Thats a good shout, I’ll check if it makes any sound with the just ignition in the morning. The sound is so faint that I can only hear it with the door closed, when I walked around the car I can’t hear anything, no unusual sounds from the engine bay either. It’s an N54 engine, 35i model.

Maybe the LPFP?

Never heard (pun) one going bad…but..

 

[Pondrew]

Roof motor in the boot constantly running? :?

 

[chaz_]

Roof motor in the boot constantly running? :?

Could be, I had the roof down this morning on the way to work and didn’t hear it after putting the roof back up. I’ll see if I can hear it tonight. The salmon relays were replaced 3 years ago so maybe time to get some more.