Used BMW 1 Series Water Pump

This question spans the E82/E87/E88 generation (2004–2013) and the F20/F21 generation (2011–2019), which are fundamentally different platforms with different engines, so a water pump from the first generation will not cross to the second. Even within each generation, fitment is driven by the engine code rather than the model year, so supply your engine code (from your V5 or a VIN check) to the breaker and they can confirm whether a specific unit matches yours.

The 118d and 120d are badged differently but have at times shared the same engine family, meaning the water pump may well be the same part — however this depends entirely on the engine code, not the badge. Check your engine code on your V5 or via a VIN check and pass it to the breaker, as there were several diesel engine variants used across the 1 Series range and the code is the only reliable way to confirm a match.

No, trim level makes no difference to water pump fitment on the BMW 1 Series — SE, Sport, M Sport, and M135i aside, the water pump is determined entirely by the engine code, not the trim. The one exception worth noting is that genuine M variants such as the 1M or M135i/M140i carry different engines and will need the pump specific to those engine codes, so confirm your engine code with the breaker regardless of badge.

The F20 generation (2011–2019) was offered with a range of petrol and diesel engines across that period, and the water pump is specific to the engine code rather than the year or fuel type alone. Your engine code will be on your V5 registration document or can be retrieved via a VIN check, and passing that code to the breaker is the single most reliable way to ensure the part they supply matches your vehicle.

The F20 received a facelift in 2015, but whether the water pump changed across that boundary depends on the specific engine code fitted to each car rather than the facelift date itself. Some engine variants ran unchanged across the facelift while others were updated, so name the boundary to your breaker and have both engine codes to hand — they can then confirm whether the units are interchangeable for your particular engine.

No — petrol and diesel engines in the BMW 1 Series are entirely different units with different water pump designs, and year or generation alone is not enough to make them compatible. Always quote your engine code to the breaker rather than relying on year or fuel type, as that code is what determines which water pump is correct for your car.