The brief
The E200 came in with the windscreen washer doing almost nothing useful: instead of two strong jets up the glass it was producing a weak dribble that landed at the bottom of the screen. The owner had already done the obvious things, topped up the washer fluid and had a look for anything obviously loose, and it was still weak. So it came in for a proper look.
The washer motor is a small electric pump in the bottom of the fluid reservoir. It pushes the fluid up the lines to the jets at pressure. When it ages, the bearings drag and the pump element wears, so it still runs and still draws current, it just can't build the pressure to throw a proper jet. That matched the symptom exactly.
The diagnosis
We checked the easy stuff first: the fuse and the wiring were clean, and the tank was full. Then the washer motor went on a bench test. It drew current fine, so the electrics were doing their job, but it was pumping at well below its rated pressure. Bearings dragging, pump worn. Cleaning it isn't a fix for that, it needs replacing.
While the car was up, a look round the engine found a couple of the engine mounts getting tired, the rubber softened with age, so those went on the list to do at the same time rather than ask the owner back for a second visit.
The work
The under-bonnet access trim came off, the old washer motor was dropped out of the reservoir, and a new Mercedes-spec pump went in with fresh sealing grommets so it doesn't weep around the tank. The harness and supply line were reseated, the tank refilled, and both windscreen jets re-aimed so they hit the centre of the wiper sweep instead of the bottom of the glass.
While the car was in, the tired engine mounts were swapped for new Mercedes-spec units, which is what keeps the engine's vibration from working its way into the cabin.
Then everything was tested: washers, wipe pattern, and a run to check the engine sat quieter.
The outcome
Two strong jets up the glass on the first press, and a clean wipe pattern after, no streaks, no dribble.
The E200 went home with the washers behaving the way they should, and with fresh engine mounts in place of the tired ones, which keeps the engine's vibration from coming through into the cabin on idle and on gear changes. Two small jobs in one visit, both the kind that quietly make the car nicer to live with.
