[kromix]

What is this and where does it come from? I don't take my car off-roading where does this buildup come from, what is it and how do I get rid of it, it's caked on so hard?

My car is only on urban streets, no dirt, what the hell is this? It's on both sides, where the door panels are, same spot.

[Presario]

It's some sort of joint lubrication BMW uses when they transport the car. Had that on my car as well. It is caked on pretty hard so use some detailer's spray and a soft microfiber towel to rub it off.

[claykin]

On my car it looks like its coming from the water weep holes in the door. Some goo to protect metal from corrosion?

All my past BMW's had it too. Seems to lessen/cease after a year or so.

[giggity317]

I don't think either of these answers above are correct.

Those marks are from water runoff anytime I rains, you use the windshield wipers or you wash your car and don't use a air compressor to dry it completely. Water from the side and roof drain here. Pour a cup of water along side the b pillar and you'll see.

I have this on my F30 and would have to continually whip it off/clean while I was washing it. It's a little frustrating because no matter how dry I thought I got my var, water would still drain here.

[ejholt]

I've got the same issue. Looks like grease and I can't seem to get it clean. Really stands out on the EBII.

[Presario]

The reason I know is I saw my car fresh from the transport with all the protective wrapping still on and it had the grease stains on both side skirts. They told me it was lube to protect joints on the doors from transport. It is yellow in color. My detailer said the fluid will leak from time to time over the course of the first year and that he's seen it many times on BMWs.

[pallymore]

It happens on my car too.

Yes, at first it was yellowish lube thing, it didn't go away after a few washes. If you take a look at the driver's door panel you should be able to see a small hole near the bottom left corner, that's where the yellow fluid comes from.

But when it stops "leaking" the yellow fluid, as someone mentioned above, water drains here and you will get black marks, it's the dirt in the water.

I opti coated my car, but I still see them reappearing within one week after washing it.

[AWF30MSPORT]

Originally Posted by kromix

What is this and where does it come from? I don't take my car off-roading where does this buildup come from, what is it and how do I get rid of it, it's caked on so hard?

My car is only on urban streets, no dirt, what the hell is this? It's on both sides, where the door panels are, same spot.

If it's sticky/greasy and difficult to remove, it's cosmoline (rust preventer), but even after any cosmoline is washed away and/or drained from the weep holes, dirt, etc. will accumulate there as dirts water drains in that spot, I always get traces of dirt there after a couple of days driving and then a bit of rain. Do a quick search of the forums for "cosmoline" you will kind many post about how to clean it up effectively.

[RoundelM3]

I don't get this on my car, but I agree it looks like cosmoline, maybe even some sort of door lubricant?

[dsgs]

I think it's the cosmoline from shipping, slowly leaking from the door drain. It's messy (especially on my silver car), but it's better than the doors rusting through after shipping (ocean salt water air isn't good for your car).

[canbmw]

^Thats exactly what it is. I can see it in all of the drain holes in all doors on my F31. Should lessen over time but definitely a pain to clean off.