The brief
The C180 was due for its air filter and cabin filter, and the owner wanted them done, the right instinct. These two are easy to forget because nothing dramatic happens when they clog, but they matter more than they look. The engine air filter cleans the air going into the engine, and a clogged one chokes the intake and lets fine particles, dust as small as a grain of sand, slip through a tired filter and wear the engine. The cabin filter cleans the air coming into the cabin through the aircon, and a clogged one loads up with dust and pollutants, weakens the airflow at the vents, and lets stale, unhealthy air circulate. Both are scheduled wear items, and it's worth fitting quality filters so they do their job for the full interval.
The diagnosis
A check confirmed both were done: the engine air filter loaded with the dirt it had caught, restricting the intake, and the cabin filter clogged with dust, choking the airflow and making the air inside stale. Nothing else flagged, just the two filters at the end of their life. So it was a straight filter replacement, the correct quality parts for both, fitted properly and the airflow checked.
The work
The old engine air filter was removed and a new genuine-quality Mercedes-spec filter fitted, the airbox cleaned out before it closed up. The cabin filter was removed from behind the dash and a new one fitted, the housing checked clean. With both in, the intake and the aircon airflow were checked to confirm they were flowing as they should. A quick run confirmed strong airflow at the vents, fresh air in the cabin, and clean intake to the engine.
The outcome
Cleaner air to the engine, strong airflow at the vents, fresh air in the cabin, and both filters reset for the next interval. The C180 went home with the filters sorted. They're small, cheap parts that protect the engine and the air you breathe, so changing them on schedule with quality filters is exactly the kind of maintenance that pays for itself quietly.
