The brief
The C180 was in for its scheduled service. No complaints, nothing wrong that the owner had noticed, just the car brought in on time at its interval. That's the kind of visit we like, the one where the job is to keep things right rather than fix something that's gone wrong.
A proper service on a Mercedes is more than an oil change. It's a chance to go over the whole car while it's on the lift, change the consumables that are due, scan the electronics for anything brewing quietly, and reset the service counter so the next interval is timed correctly.
The diagnosis
The STAR scan came back clean, no stored fault codes anywhere in the car. Brake fluid moisture content was within spec, the battery passed its load test, and the belts, hoses, suspension and underbody all looked good.
What was due, though, was a fair bit. The engine air filter and the cabin filter were both dirty enough to change rather than leave another interval, and the spark plugs had reached their service point, the old set showing the wear and crusting you'd expect at that mileage. So this turned into a fuller service than just oil and filter.
The work
We drained and refilled the engine oil with the correct Mercedes spec and fitted a new oil filter. The engine air filter and the cabin filter were both replaced with fresh ones, and a new set of four Mercedes-spec spark plugs went in to replace the worn ones.
Coolant, brake fluid and washer fluid were topped to their marks. The service indicator on the cluster was reset through STAR so the next due date is right, and every reading was written into the service log.
The outcome
Clean scan, fresh oil and filter, new air and cabin filters, new plugs, fluids topped and the service light reset. Everything else either fresh or noted and signed off as good.
The C180 went home good for another interval, with a service record that shows exactly what was done. Servicing on time, before anything complains, is the cheapest way to run a car like this.