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

waxfigure · 08-21-2019, 02:40 AM

I posted this thread on "N55 (M235i) Engine, Transmission, Exhaust, Tuning". Please remove this thread!

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!!

john16443 · 08-25-2019, 09:09 PM

I see this as normal oxidation layer for aluminum. Nothing to worry about or try to clean up. Your 2016 could have been in service for almost 4 years now, and it may have been a car from outside Southern CA. It is nothing to worry about, and will not affect the engine whatsoever. It is normal for all metals to oxidize when exposed to the atmosphere, some grades of stainless steel show oxidation as well, while other stainless grades show barely any at all. What's important is there isn't any oxidation on the inside of that aluminum casting for the oil filter housing. If you ever happen to take off that oil filter cap and look inside, you'll find it clean as a whistle.

Kgare · 08-26-2019, 05:01 AM

Previous owner might have used strong cleaning chemical.

liebetrau88 · 08-26-2019, 12:02 PM

Aluminum oxidation. It's normal.

MarcoZandrini · 08-27-2019, 11:19 AM

I bet the car has lived most of its life near the ocean.

morphomeman · 08-29-2019, 02:53 AM

My cars spend their lives next to the ocean, but garaged. Some oxidation, because you can't avoid air altogether, but not terrible. As noted, it's the alumin(i)um, babe.

waxfigure · 09-01-2019, 10:45 PM

Quote:

Originally Posted by MarcoZandrini

I bet the car has lived most of its life near the ocean.

According to the records, it lived in Newport beach since it was first leased. Now it's in manhattan beach with me so I guess there's just no way to escape the oxidation

Unicorn123 · 09-02-2019, 07:47 AM

wax,

Your conclusion is correct, you cannot prevent oxidation on aluminum. In fact, aluminum will immediately oxidize when exposed to air if it is a virgin surface.

Being on the coast with moist air which may have a some chloride content, this is normal and will not be an issue for your car, although it is not as pretty cosmetically!

We have this issue in New England with coastal air and salty roads in the winter!

waxfigure · 09-02-2019, 04:41 PM

Quote:

Originally Posted by Unicorn123

wax,

Your conclusion is correct, you cannot prevent oxidation on aluminum. In fact, aluminum will immediately oxidize when exposed to air if it is a virgin surface.

Being on the coast with moist air which may have a some chloride content, this is normal and will not be an issue for your car, although it is not as pretty cosmetically!

We have this issue in New England with coastal air and salty roads in the winter!

Thanks for the validation. I have a question tho.. My buddy owns 2014 228i and he lives in manhattan beach as well. He got the car brand new but his car does not seem to have any oxidation or not as much oxidation as mine (it's 5 years old). Do you think parking the car outside vs garage also has an impact on this?

Unicorn123 · 09-02-2019, 07:18 PM

Hmmm, hard to tell. I expect that if the car is outside, it has a better chance of being exposed to humid or damp air. versus in the garage. I know my car fares better in the garage; however, it is a converted carriage house and my house was build in the 1700's so my garage is not climate controlled, it is controlled by the climate!

Once it comes out however, all bets are off. Proximity to the ocean, etc. are all variables here.

In other words, no clue...sorry for the useless response. Perhaps another west coastal dweller has a better explanation.

08-21-2019, 02:40 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) I posted this thread on "N55 (M235i) Engine, Transmission, Exhaust, Tuning". Please remove this thread! 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 Last edited by waxfigure; 08-21-2019 at 02:49 AM..
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08-25-2019, 09:09 PM	#2
john16443 First Lieutenant 47 Rep 370 Posts Drives: 2017 M240i Join Date: Dec 2012 Location: Ramona, CA iTrader: (4)	I see this as normal oxidation layer for aluminum. Nothing to worry about or try to clean up. Your 2016 could have been in service for almost 4 years now, and it may have been a car from outside Southern CA. It is nothing to worry about, and will not affect the engine whatsoever. It is normal for all metals to oxidize when exposed to the atmosphere, some grades of stainless steel show oxidation as well, while other stainless grades show barely any at all. What's important is there isn't any oxidation on the inside of that aluminum casting for the oil filter housing. If you ever happen to take off that oil filter cap and look inside, you'll find it clean as a whistle.
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08-26-2019, 05:01 AM	#3
Kgare Enlisted Member 7 Rep 30 Posts Drives: F23 M235 Join Date: Jun 2016 Location: RSA iTrader: (0)	Previous owner might have used strong cleaning chemical.
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08-26-2019, 12:02 PM	#4
liebetrau88 Second Lieutenant 106 Rep 237 Posts Drives: 2017 M240i xDrive Join Date: Aug 2018 Location: Minnesota iTrader: (0)	Aluminum oxidation. It's normal.
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08-27-2019, 11:19 AM	#5
MarcoZandrini Major 444 Rep 1,264 Posts Drives: 2018 M240i Join Date: Jun 2017 Location: Virginia iTrader: (0)	I bet the car has lived most of its life near the ocean.
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08-29-2019, 02:53 AM	#6
morphomeman Major 593 Rep 1,219 Posts Drives: 2015 M235ix Join Date: May 2015 Location: United States iTrader: (1) Garage List 2016 BMW X3 [0.00] 2015 BMW M235ix [0.00]	My cars spend their lives next to the ocean, but garaged. Some oxidation, because you can't avoid air altogether, but not terrible. As noted, it's the alumin(i)um, babe.
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09-02-2019, 07:47 AM	#8
Unicorn123 Second Lieutenant 187 Rep 255 Posts Drives: 2016 M235i xDrive Join Date: Oct 2018 Location: Hartford, CT iTrader: (0)	wax, Your conclusion is correct, you cannot prevent oxidation on aluminum. In fact, aluminum will immediately oxidize when exposed to air if it is a virgin surface. Being on the coast with moist air which may have a some chloride content, this is normal and will not be an issue for your car, although it is not as pretty cosmetically! We have this issue in New England with coastal air and salty roads in the winter! __________________ Current Fleet, 16 F22 M235i xDrive, 15 Audi Q5 3.0 TDI (my Wife's), 07 E85 Z4M Roadster, 01 Toyota Tundra 2wd Long Bed Retired (a few of them...), 08 E60 550i 6M, 01 Audi S4, 70 Fiat 124, 88 E28 M5, 72 Datsun 510 2Dr, 73 TR6
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09-02-2019, 07:18 PM	#10
Unicorn123 Second Lieutenant 187 Rep 255 Posts Drives: 2016 M235i xDrive Join Date: Oct 2018 Location: Hartford, CT iTrader: (0)	Hmmm, hard to tell. I expect that if the car is outside, it has a better chance of being exposed to humid or damp air. versus in the garage. I know my car fares better in the garage; however, it is a converted carriage house and my house was build in the 1700's so my garage is not climate controlled, it is controlled by the climate! Once it comes out however, all bets are off. Proximity to the ocean, etc. are all variables here. In other words, no clue...sorry for the useless response. Perhaps another west coastal dweller has a better explanation. __________________ Current Fleet, 16 F22 M235i xDrive, 15 Audi Q5 3.0 TDI (my Wife's), 07 E85 Z4M Roadster, 01 Toyota Tundra 2wd Long Bed Retired (a few of them...), 08 E60 550i 6M, 01 Audi S4, 70 Fiat 124, 88 E28 M5, 72 Datsun 510 2Dr, 73 TR6
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