Drain hole at fuel fill door?

[Stilllearning6]

1998 740iL:

My fuel fill area has rust inside the door area.

I sanded the rust and then I could see a hole staring at me.

Is this an OEM water drain hole or did the metal rust through all way?
I read in the forms that some BMW models had a drain hole that folks had to clear with a poker.
Not sure if this is it.

Any guidance on proper treatment of this rusty area after I scrape/sand as much rust as I can get?

I have rust converter. I have metal etching primer.
I do not believe that I will be able to get all the rust down to shiny metal especially at the body side edge.
The rust has reached the seam where the fuel fill area meets the passenger rear quarter panel side.

[tjpike]

there was no hole there from factory, maybe the rust ate through?

[Qsilver7]

Ditto...no hole in my 97 e38:

But my 06 e53 does have a drain hole...located on the far right...below the hinge and has a plastic insert to help prevent rust:

[Stilllearning6]

Thank you ,gents.

Will study internet regarding rust treatment/repair.
Perhaps I should drill the hole to get clean metal, then add Bondo to block the hole.

I like the drain hole idea, yet I do not know what lies beneath the hole area.
Sealing the hole might prevent further damage.

[Qsilver7]

I like the drain hole idea, yet I do not know what lies beneath the hole area.
Sealing the hole might prevent further damage.

On the e53 X5 which has the drain...there's a tube attached that drains the water to the ground similar to your AC condensate lines. See #21 (drain grommet) and #17 (outlet pipe) in the e53 diagram below:

http://bmwfans.info/parts-catalog/E5...ttaching_parts

[Frankie]

My guess is the previous owner poked a hole there. Over time, as water got underneath the paint, rust formed.

I bet if you removed the wheelhouse liner and looked up, you'd see the hole. You'd also be able to see if the rust has spread beyond the filler door area.

I'd fill the hole with Bondo and then paint it.

[Stilllearning6]

More 60 grit sanding and 3 applications of "Crud Cutter Rust Remover: Must for Rust". Slow progress because of years of rust neglect.

I drilled to clean the sides of hole with 1/4 bit! Much larger than I imagined.

I will plug hole.
I am leaning toward a rubber or plastic 1/4 inch plug/stopper/cover.
That way , I will have the flexibility to remove the plug/stopper/cover.

Hope that the Crud Cutter will allow me to prime it with metal primer and then a top coat paint.
Not sure what will happen at transition areas.
It may delaminate over time.
I have to do something.

Next : use finer grits to get from #60 --> #400. Then, more Crud Cutter, wipe with water to remove Crud Cutter film, wipe with degreaser, prime.

I appreciate the guidance from all.