[sympathydropout]

Hey everyone, just bought a one owner 2018 F87 M2 in LBB, 47k miles, manual transmission, no accidents. The car was based in Alberta Canada its whole life and was the only low miles one owner non accident I could find in the entire country for the right price. I couldn’t inspect the car first as it was in Washington and I’m in Los Angeles. Took delivery of the car, which is perfect cosmetically and interior wise a 10/10. I love it so far and was giving her a good wash, had a look at the undercarriage and my heart sank when I noticed these surface rust spots. Can someone help me determine how serious this is? Cosmetically the car is perfect, but this worries me and would love some piece of mind without brining it in for service / opening Pandora’s box if not necessary. Any help greatly appreciated

[MikeF87LCI]

Here in the UK this would be pretty normal car around this age….they salt roads pretty heavily in bad weather which really contributes to stuff like this.

But looks like it’s just the rear subframe, that’s only thing under there that’s steel. The front subframe is aluminium, along with the suspension arms.

Just keep an eye on the suspension coils/spings as paint can crack or rub off these and trap water which can also lead to corrosion of the spring and ultimately the spring failing. Not ideal!

But yeah what you see there can be treated, or even powder coat subframe if you wanted to.

[philth]

What’s all that on the diff?

[allinon72]

This is normal for a car driven in winter conditions. The rust you see is surface rust on the painted metal surfaces, which will happen with snow and salt. It is not dangerous or structural. Now that the car is in LA, it will effectively stop for the most part.

Originally Posted by philth

What’s all that on the diff?

Aluminum corrosion, again from winter exposure. It's likely most or all of the aluminum parts on the underside and in the engine bay will be in this condition.

[///MPhatic]

I'd put some rust converter on it if I were you, just in case. It's easy just to brush it on, you don't even have to wipe it off.

This is the one I use, works fantastic. https://www.homedepot.com/p/Krud-Kut...R326/203396826

[sympathydropout]

Thank you everyone for the replies, I was having a mini heart attack worrying for a sec this morning! Genuinely appreciate all the help. I will pick that product up and also keep an eye on it moving forward🫡👍

[Philly_sweden]

Chill man! 100% normal and only surface rust and only cosmetical.

Steel brush/wool and black paint/rubber/undercarriage paint.

It’s just a car and meant to be driven

We have tons of salt here in Europe and the car is made here.

Just drive it and enjoy it!

But! Inspect or change the springs! They snap so easily especially when corroded! It’s not if but when!

Oh and, congratulations!