Should I be worried about this what looks like rust ?

fe7565 · 10-28-2025, 08:11 PM

Featured on BIMMERPOST.com

2012 car, garaged, DC area. To me it looks like rust, but I’m not 100% sure if I should take it down to the bare metal, prime, and repaint it. This is in my engine compartment front area.

MMnut · 10-28-2025, 08:29 PM

Doesn't look like rust. Try with the plastic knife to scrape it off.

fe7565 · 10-28-2025, 08:51 PM

I took the photos shortly before I posted them, and I didn’t even look at them up close. Now that I could see them on the big screen, I think you are correct. This is some sort of a liquid dried on it.

MisanoblueZ4 · 10-28-2025, 09:22 PM

Definitely not rust.

vt100 · 10-29-2025, 01:11 AM

that's most likely cosmoline.

jzeiler4 · 11-06-2025, 08:38 PM

BMW coats the inside of the hood with that stuff, on a hot day it drips out and makes a mess.

fe7565 · Yesterday, 04:27 PM

Just to close the loop on this. It was just some deposit from the cleaning stuff I used that accumulated and then got baked on due to under the hood engine heat. Came off with little effort.

10-28-2025, 08:11 PM	#1
fe7565 Colonel 1117 Rep 2,704 Posts Drives: 2012 BMW 328i N26 Join Date: Nov 2013 Location: United States iTrader: (0)	Should I be worried about this what looks like rust ? Featured on BIMMERPOST.com 2012 car, garaged, DC area. To me it looks like rust, but I’m not 100% sure if I should take it down to the bare metal, prime, and repaint it. This is in my engine compartment front area. Attached Images __________________ Help each other: if you manage to fix your issue (especially with help from this forum), don't be a d*ck and disappear. Follow-up by posting the solution so you can help others.
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10-28-2025, 08:29 PM	#2
MMnut Lieutenant 660 Rep 497 Posts Drives: M4 Join Date: May 2021 Location: AU iTrader: (0)	Doesn't look like rust. Try with the plastic knife to scrape it off.
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10-28-2025, 08:51 PM	#3
fe7565 Colonel 1117 Rep 2,704 Posts Drives: 2012 BMW 328i N26 Join Date: Nov 2013 Location: United States iTrader: (0)	I took the photos shortly before I posted them, and I didn’t even look at them up close. Now that I could see them on the big screen, I think you are correct. This is some sort of a liquid dried on it. __________________ Help each other: if you manage to fix your issue (especially with help from this forum), don't be a d*ck and disappear. Follow-up by posting the solution so you can help others.
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10-28-2025, 09:22 PM	#4
MisanoblueZ4 Lieutenant Colonel 5160 Rep 1,980 Posts Drives: 2021 Z4 M40I Join Date: Sep 2023 Location: South Carolina iTrader: (0)	Definitely not rust.
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10-29-2025, 01:11 AM	#5
vt100 Lieutenant 404 Rep 518 Posts Drives: '06 Z4MC, '12 128i Join Date: Apr 2019 Location: SFO iTrader: (1)	that's most likely cosmoline.
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11-06-2025, 08:38 PM	#6
jzeiler4 Captain 376 Rep 651 Posts Drives: 2021 M240i xDrive F23 Join Date: Aug 2020 Location: Hazel Green, AL iTrader: (0)	BMW coats the inside of the hood with that stuff, on a hot day it drips out and makes a mess.
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Yesterday, 04:27 PM	#7
fe7565 Colonel 1117 Rep 2,704 Posts Drives: 2012 BMW 328i N26 Join Date: Nov 2013 Location: United States iTrader: (0)	Just to close the loop on this. It was just some deposit from the cleaning stuff I used that accumulated and then got baked on due to under the hood engine heat. Came off with little effort. __________________ Help each other: if you manage to fix your issue (especially with help from this forum), don't be a dck and disappear. Follow-up by posting the solution so you can help others. Last edited by fe7565; Yesterday at 04:35 PM..*
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