Rusting Exhaust

[JimsM6]

When I had my 2013 535i on my lift this morning, I discovered severely rusting segments, maybe 6 inches long, on each pipe just before they enter the front muffler. I'm guessing that exhaust moisture cools and condenses in those short segments, causing rust from the inside out.

I'm disappointed to learn that BMW doesn't use stainless exhaust pipes. The rest of the exhaust system looks like new after 45,500 miles in my always garaged car. I guess the pipes are aluminized steel. Admittedly, the car does make a lot of short trips, which undoubtedly cause the problem. When one of the pipes finally rusts through, I'll probably take it to a muffler shop and have those pipe sections replaced rather than paying an exorbitant price to replace that portion of the system that includes the muffler, which so far shows no damage.

Has anyone else experienced this problem?

[MarcoZandrini]

We have to remember that all car makers are trying to lighten their cars. Stainless steel isn’t light (nor cheap!) so I’m not surprised BMW has reverted to a lighter, less corrosion resistant material. Your strategy sounds correct-fix it when it goes bad.