Nissens 91398 Automatic Transmission Oil Cooler

Automatic Transmission Oil Cooler for BMW and Mini

Nissens 91398 is an aluminum automatic transmission oil cooler built for select BMW and Mini applications from 2019-2023. It is designed for direct-fit service on vehicles listed below, including BMW 228i Gran Coupe, BMW X2, BMW X1, and Mini Cooper models.

Key Features

• Aluminum cooler construction for thermal efficiency and corrosion resistance
• Core dimensions: 5.39 in. length, 3.3900 in. height, and 3.34 in. width
• 15-core-row design for fluid heat exchange
• 0.57 in. inlet and outlet diameters
• No gasket or seal included
• Cross-reference: 24148699905

Product Details

This Nissens automatic transmission oil cooler, part number 91398, is engineered for transmission fluid temperature control in BMW and Mini vehicles that use the listed configuration. Nissens develops thermal management components to OE-level standards, and this cooler follows that focus with an aluminum core and compact dimensions suited to the factory application. It fits 2021-2023 BMW 228i Gran Coupe, 2021-2023 BMW 228i xDrive Gran Coupe, 2019-2023 BMW X2, 2020-2022 BMW X1, 2020-2023 Mini Cooper, 2020-2023 Mini Cooper Clubman, and 2020-2023 Mini Cooper Countryman, all without housing where noted.

Common Issues This Part Can Address

• Transmission fluid running hotter than normal
• Reduced cooling performance in the transmission fluid circuit
• Leakage or damage at the original cooler assembly
• Service replacement for a worn or contaminated cooler
• Fitment correction for vehicles requiring the without-housing configuration

Installation Notes

Verify the vehicle’s cooler layout and confirm the without-housing requirement before installation. Check inlet and outlet sizing against the original unit, and inspect mating surfaces carefully since no gasket or seal is included. For best results, flush the transmission cooling circuit and confirm there is no debris or contamination before returning the vehicle to service.

Quality Assurance

Nissens positions its thermal management parts around consistent manufacturing quality and ongoing aftermarket development. Part number 91398 is built as a replacement transmission oil cooler for the confirmed BMW and Mini fitments listed above.