That they were gonna put fucking advertising inside my luxury vehicle

Yeah, I wish more mechanics wrote up on what to expect wrt faults, failures, common leaks etc. would be nice to know for planning purposes and preventative maintenance.

Not an owner, but I've been going through NHTSA's complaint data for the F30/F31/F34 3 Series (2012-2018), so here's what US owners actually filed. There are 1,215 complaints through mid-October 2026, and the engine leads with 29% of them, at a median of 64,000 miles where an odometer was given.

The documented big one is the N20/N26 timing chain guides: the plastic guides embrittle, the chain stretches or jumps, and the engine is often destroyed, typically around 50-80k miles. BMW of North America extended timing chain coverage to 7 years / 70,000 miles, and a US class action covered 2012-2015 cars. Smaller but common: N20 oil filter housing and valve cover gasket leaks, and N55 valve stem seals (blue smoke on startup) on 2012-2015 cars. Electrical is second at 23% of complaints.

Curious whether your yard sees the timing chain failures as often as the complaints suggest.

https://mileagecurve.com/bmw-3-series-2012-2018/ (I run this site)