B4204T11 is the engine type - VEA/Drive-E 4-cylinder petrol T5. 1472609 is the sequential engine number.
Boroscope and/or pressure test is what they should have done from the start. The old-fashioned (practical) way of diagnosing a defect. Back to where we started - if coolant is being lost and nothing is obvious externally, there has to be an issue inside the engine.
And no, it's very unlikely to be a manufacturing defect. Presumably the car hasn't being losing coolant from new? But overheating or poor coolant circulation due to the pump defect is a very likely cause.
Boroscope and/or pressure test is what they should have done from the start. The old-fashioned (practical) way of diagnosing a defect. Back to where we started - if coolant is being lost and nothing is obvious externally, there has to be an issue inside the engine.
And no, it's very unlikely to be a manufacturing defect. Presumably the car hasn't being losing coolant from new? But overheating or poor coolant circulation due to the pump defect is a very likely cause.