The brief
The 216i's windscreen washers were giving a weak dribble down the glass instead of two proper jets, and the owner had noticed a small drip forming under the washer tank.
Two faults, both at the washer system. The dribble means the pump is not building the pressure it should. The drip means something is leaking, and on this setup it is almost always the seal where the pump body pushes into the tank wall. Neither is a big job on its own, but you want both sorted before the first heavy rain, or a muddy stretch behind a truck, leaves you with a windscreen you cannot clear.
The diagnosis
On the bench the washer pump was tested on its own, and it was pumping at well below the pressure it is rated for. The pump element inside had simply worn down, so it could no longer push fluid through the jets hard enough to make a proper spray.
A closer look found the cause of the drip too: the O-ring around the pump body had hardened and was no longer sealing. So both problems traced back to the same part. Fitting a fresh pump with a new O-ring fixes the weak spray and the leak in one go, rather than nursing a tired pump along.
The work
The under-bonnet trim came off first to get at the tank. Then the old washer pump was eased out, a new BMW-spec unit fitted with a fresh O-ring, and the harness plug and supply hose reseated. The tank was topped back up.
Last job was aiming both windscreen jets, because a washer repair is only finished when the spray actually lands where the wipers sweep it, not low on the glass or up over the roof line.
The outcome
Two strong jets straight up the glass. No more drip under the tank.
The 216i went home with the washers working the way they should. It is a small fix, but it is the kind you appreciate the first time you are behind a grimy truck in the rain and need the screen clear in one sweep. And catching the leaking O-ring at the same time means no more washer fluid quietly draining away under the car.