Photos from inside oil fil cap showing coating/metal peeling off from engine/metal

[SaNGRia]

Originally Posted by dragonsi

I noticed that you and Sangria both have the same issues, and both are located in FL. It probably has to do with the salty air you guys have over there.

I am also wondering it is related to humidity. I am right at the border of Everglades and literally no one can build houses anymore behind my backyard. So I have Canal and Everglades and rains all the time. And I do not have AC in my garage.

But it shouldn't cause this problem like that! We are talkin about an Engine that heats up all the way to 210F-230F. The paint they used is not that quality then!

[TX]

Originally Posted by SaNGRia

2008 E93 M3 - 37K - Always Garage Kept - It has been driven 2 or 3 times while raining and has a really clean Engine Bay!

I've not been keeping up with this thread, but wow the posts are very interesting to read up on finally. This is exactly what mine looks like. Peeling on the inside makes me feel icky inside
Edit: it's continued on and I have a very small oil leak from valve cover gaskets on both sides. The dealer never did step up on either issue. I'm just keeping an eye on blackstone reports every 3 to 5K miles on changes done myself now. Switching to the new shell oil, but i hear its all the same stuff.

[deansbimmer]

The covers are indeed a magnesium alloy. Though it is strong and lightweight, Magnesium is one of the lowest in the galvanic series which means it is highly reactive and corrodes very easily in different environments.

These covers are coated in a ceramic oven cured coating. The inside of the covers are not fully coated, which allows contact with atmosphere. The result is corrosion over time, which causes flaking of not only the metal itself, but the coating. If there are pores in the casting allowing oxidation to reach the underside of the outer coating, then the outer coating will bubble also and eventually peel. It happens more often near the oil cap snout because it is not bathed in oil as much as the other areas (which prevents the atmospheric contact).

This can also happen inside the gasket groove which will cause persistent leaks. Since it creates a rough surface difficult for a gasket to seal against, just replacing the gasket won't solve the issue. The key to getting the dealer to replace it under warranty is right here. If you take it back repeatedly for leaking then they will eventually be forced to replace the cover too.

It's not a big deal. "If" small amounts of it fall from the valve cover inside the engine, it will make its way to the oil pan and will be filtered out within the oil filter before allowing any actual harm to the engine. In an oil analysis, it will show up in the magnesium and aluminum counts.

[romemmy]

Originally Posted by deansbimmer

The covers are indeed a magnesium alloy. Though it is strong and lightweight, Magnesium is one of the lowest in the galvanic series which means it is highly reactive and corrodes very easily in different environments.

These covers are coated in a ceramic oven cured coating. The inside of the covers are not fully coated, which allows contact with atmosphere. The result is corrosion over time, which causes flaking of not only the metal itself, but the coating. If there are pores in the casting allowing oxidation to reach the underside of the outer coating, then the outer coating will bubble also and eventually peel. It happens more often near the oil cap snout because it is not bathed in oil as much as the other areas (which prevents the atmospheric contact).

This can also happen inside the gasket groove which will cause persistent leaks. Since it creates a rough surface difficult for a gasket to seal against, just replacing the gasket won't solve the issue. The key to getting the dealer to replace it under warranty is right here. If you take it back repeatedly for leaking then they will eventually be forced to replace the cover too.

It's not a big deal. "If" small amounts of it fall from the valve cover inside the engine, it will make its way to the oil pan and will be filtered out within the oil filter before allowing any actual harm to the engine. In an oil analysis, it will show up in the magnesium and aluminum counts.

I have three of these engines with covers off from 2008 to 2011 (my original blown one from 2011, one dud one I bought, and then the one I rebuilt), and all of them have major pealing. The older ones are the worse, but even my 2011 one has major bubbling on the inside (you can't see it from the oil cap, but if you take the cover off you see it), and when cleaning the cover it just flakes off.

I have no choice but to use my 2011 cover right now so I took off all the big pieces, but this is kind of ridiculous that a marque like BMW has problems like this on such young cars...

Thanks!

S.

[SYT_Shadow]

Originally Posted by SaNGRia

I am also wondering it is related to humidity. I am right at the border of Everglades and literally no one can build houses anymore behind my backyard. So I have Canal and Everglades and rains all the time. And I do not have AC in my garage.

But it shouldn't cause this problem like that! We are talkin about an Engine that heats up all the way to 210F-230F. The paint they used is not that quality then!

it's sad because a company goes all out and uses magnesium, then it corrodes and pisses us off.

[deansbimmer]

Magnesium is nothing new for valve covers. Many makes uses Magnesium for valve covers at some point. Not just BMW but also Ford, Chevrolet, Porsche, etc.... Even back into the 90's. They all have this problem or something similar. It's inherent to magnesium- it's not a very stable alloy, the finish doesn't last.

You can't make everyone happy. If they were aluminum then we'd be all "WTF, aluminum valve covers? That's soooo 80's"....

[romemmy]

Originally Posted by deansbimmer

Magnesium is nothing new for valve covers. Many makes uses Magnesium for valve covers at some point. Not just BMW but also Ford, Chevrolet, Porsche, etc.... Even back into the 90's. They all have this problem or something similar. It's inherent to magnesium- it's not a very stable alloy, the finish doesn't last.

You can't make everyone happy. If they were aluminum then we'd be all "WTF, aluminum valve covers? That's soooo 80's"....

My Evo magnesium cover (2006 - so 5 years older than my M!) looked perfect on the inside when I rebuilt it earlier this year Mitsubishi making BMW look like fools

[1MOREMOD]

My only question is how you get inside the engine to take photos from inside the oil cap rather than of the inside of the cap.

[romemmy]

Originally Posted by 1MOREMOD

My only question is how you get inside the engine to take photos from inside the oil cap rather than of the inside of the cap.

Take the valve cover off... not difficult, but not a 5 minute job either.. it doesn’t just peel near the oil cap, but along the entire inside, so if you really want to examine it, you have to take the cover off.

Thanks!

S.

[1MOREMOD]

Got it only saw first photo of a Yellow hole

[pbonsalb]

Could you use an inspection camera or are baffles in the way?

[romemmy]

Originally Posted by pbonsalb

Could you use an inspection camera or are baffles in the way?

You could... though I’d be a little worried about hitting the flaking material with your endoscope and having it fall in to your oil ways. When left alone it bubbles up, but doesn’t seem to just fall by itself.

[pbonsalb]

The 92-95 E36 6 cylinder cars had magnesium valve covers as well and they flake inside. A few people have had them stripped and coated. But the bubbling and eventual flaking does not seem to have destroyed those motors. Still, if there is a coating solution maybe I will do it when I change the gaskets.

[K-M3]

Originally Posted by deansbimmer

The covers are indeed a magnesium alloy. Though it is strong and lightweight, Magnesium is one of the lowest in the galvanic series which means it is highly reactive and corrodes very easily in different environments.

These covers are coated in a ceramic oven cured coating. The inside of the covers are not fully coated, which allows contact with atmosphere. The result is corrosion over time, which causes flaking of not only the metal itself, but the coating. If there are pores in the casting allowing oxidation to reach the underside of the outer coating, then the outer coating will bubble also and eventually peel. It happens more often near the oil cap snout because it is not bathed in oil as much as the other areas (which prevents the atmospheric contact).

This can also happen inside the gasket groove which will cause persistent leaks. Since it creates a rough surface difficult for a gasket to seal against, just replacing the gasket won't solve the issue. The key to getting the dealer to replace it under warranty is right here. If you take it back repeatedly for leaking then they will eventually be forced to replace the cover too.

It's not a big deal. "If" small amounts of it fall from the valve cover inside the engine, it will make its way to the oil pan and will be filtered out within the oil filter before allowing any actual harm to the engine. In an oil analysis, it will show up in the magnesium and aluminum counts.

This!!!

There have been earlier threads in the years past on this very forum discussing this issue which has been found to be concerning to us owners but NOT damaging to the engine (I'm speaking of the internal flaking immediately inside the oil filler cap area )

[kyrix1st]