BMW Servicing 340i Coolant Leak Repair

A 2017 BMW 340i was brought to Auto Werkstatt after the owner noticed coolant dripping from underneath the vehicle. During the inspection, technicians confirmed a significant coolant leak coming from one of the main molded radiator hoses. The hose had been routed too close to the crank pulley, causing it to rub against the pulley until a large hole developed.

The damaged hose was identified as BMW part #17 12 8 633 482. Technicians also observed signs of coolant leakage on the left side of the engine. The recommended first step was to replace the damaged hose and route it properly to prevent further contact with the crank pulley. After replacement, a cooling system pressure test would be needed to determine whether any additional leaks were present.

The inspection also identified several other maintenance concerns. The check engine light and tire warning light were illuminated. The left rear tire was bald, and technicians recommended replacing both rear tires together. The rear brake pads had approximately 3–4 mm of material remaining, indicating that their condition should be monitored and replacement planned as needed.

Additionally, technicians found a leak at the rear differential and recommended replacing the pinion seal to address the issue. The remaining inspection items did not note any other concerns.

Auto Werkstatt’s inspection identified the source of the BMW’s major coolant leak and outlined the next steps for repair and further testing. The inspection also brought attention to the rear differential leak, worn rear tire, low rear brake pad thickness, and illuminated warning lights, giving the owner a clearer understanding of the vehicle’s immediate repair needs and upcoming maintenance priorities.