Engine Oxidation or Salt? what stuff on the engine (N55)

waxfigure · 08-21-2019, 02:46 AM

Hello! I recently purchased a CPO 2016 m235i with 36k miles in Irvine California.

I noticed these white spots on my engine, which appears to be only on the aluminum part of the engine, at the time of purchase but the dealer said it was completely fine. When I got home and tried to wipe off some of the white part, it left these black marks.

I purchased extended platinum warranty for the next 6 years/ unlimited miles so I know that I will be covered but I have never seen this before and wanted to confirm if anyone else has seen this before.

I noticed that there was just one other post on the forum regarding the same problem on a car that is only 7 months old (at the time of the post) but it never confirmed if it was indeed oxidation or leaking coolant.

Can someone please tell me what is causing this and if this is damaging to the engine? On some posts, it says that aluminum oxidation actually creates a protective layer.. is this true?

Thank you for your help!!

bbnks2 · 08-21-2019, 09:15 AM

aluminum rust (oxidation).

XutvJet · 08-21-2019, 10:10 AM

Surface oxidation, likely caused by someone washing a warm motor with a degreaser (typically the dealer prepping the car for sale). It's harmless. If it bothers you, you can buff it off pretty easily.

waxfigure · 08-21-2019, 07:49 PM

Quote:

Originally Posted by XutvJet

Surface oxidation, likely caused by someone washing a warm motor with a degreaser (typically the dealer prepping the car for sale). It's harmless. If it bothers you, you can buff it off pretty easily.

Thanks for the confirmation!! It doesn't bother me now that I know it is harmless

08-21-2019, 02:46 AM	#1
waxfigure Member 6 Rep 28 Posts Drives: M235i Join Date: Aug 2019 Location: California iTrader: (0)	Engine Oxidation or Salt? what stuff on the engine (N55) Hello! I recently purchased a CPO 2016 m235i with 36k miles in Irvine California. I noticed these white spots on my engine, which appears to be only on the aluminum part of the engine, at the time of purchase but the dealer said it was completely fine. When I got home and tried to wipe off some of the white part, it left these black marks. I purchased extended platinum warranty for the next 6 years/ unlimited miles so I know that I will be covered but I have never seen this before and wanted to confirm if anyone else has seen this before. I noticed that there was just one other post on the forum regarding the same problem on a car that is only 7 months old (at the time of the post) but it never confirmed if it was indeed oxidation or leaking coolant. Can someone please tell me what is causing this and if this is damaging to the engine? On some posts, it says that aluminum oxidation actually creates a protective layer.. is this true? Thank you for your help!! Attached Images
	Appreciate 0 Tweet Quote

08-21-2019, 09:15 AM	#2
bbnks2 Colonel 1207 Rep 2,025 Posts Drives: 135i N55 Join Date: Jan 2017 Location: NY iTrader: (0)	aluminum rust (oxidation).
	Appreciate 0 Quote

08-21-2019, 10:10 AM	#3
XutvJet Major General 5551 Rep 5,369 Posts Drives: 2011 Cayman Base, 2016 M235 Join Date: Mar 2016 Location: Kansas City iTrader: (-1)	Surface oxidation, likely caused by someone washing a warm motor with a degreaser (typically the dealer prepping the car for sale). It's harmless. If it bothers you, you can buff it off pretty easily. __________________ The forest was shrinking, but the Trees kept voting for the Axe, for the Axe was clever and convinced the Trees that because his handle was made of wood, he was one of them.
	Appreciate 0 Quote