BMW S65 DCT / 6-Speed Dual-Pass Transmission Cooler - CSF Racing 8042

Product Information

The CSF High-Performance Transmission Oil Cooler is a direct-fit cooling upgrade for the BMW E90, E92 and E93 M3 equipped with the S65 V8 engine and seven-speed dual-clutch transmission.

Transmission fluid temperatures can rise considerably during spirited driving, track use and repeated high-load operation. Excessive heat can reduce fluid performance and place additional thermal stress on the transmission, seals and other internal components.

CSF uses its air-conditioning condenser technology to replace the factory cooler with a high-efficiency, CAB-brazed plate-type design. Its single-row, super-high-pressure 22 mm microtube contains 11 internal channels, providing increased heat-transfer capability in a compact and durable package.

A dual-pass core directs the transmission fluid through 11 cooling tubes compared with the factory cooler's 10-tube design. High-density multi-louvered fins provide approximately 20% more surface-area contact than the original unit, helping the cooler transfer heat more efficiently during sustained high-load operation.

• Designed for the BMW E90, E92 and E93 M3
• Compatible with the S65 4.0-litre V8 engine
• Direct replacement for the factory transmission oil cooler
• Single-row, 22 mm (0.87 in) super-high-pressure microtube
• Eleven internal microtube channels
• Dual-pass high-performance cooling configuration
• Eleven cooling tubes compared with the factory 10-tube design
• High-density multi-louvered fin construction
• Approximately 20% more surface-area contact than the factory cooler
• Laboratory tested at approximately 30% greater efficiency than the factory cooler
• Retains the original oil-line connections
• Compatible with the factory mounting brackets and shroud ducting
• True plug-and-play installation with no cutting or modifications required

Cooling Performance

The dual-pass configuration increases the amount of time the transmission fluid remains in contact with the cooling surface. Combined with the 11-tube core and high-density multi-louvered fins, this design provides approximately 30% greater cooling efficiency than the original unit under laboratory testing.

Improved transmission-fluid temperature control is especially beneficial during track driving, spirited street use and other conditions involving sustained acceleration, repeated shifting and elevated drivetrain temperatures.

Quality and Testing

CSF operates ISO-certified manufacturing facilities and supplies cooling components to automotive manufacturers in the United States, Germany and Asia. Its performance cooling products are manufactured using the same production standards applied to its original-equipment cooling components.

CSF cooling products are subjected to rigorous quality-control procedures that may include hydrostatic testing, vacuum-decay testing and lifecycle testing to verify sealing, durability and long-term performance.

Installation

The transmission oil cooler is designed as a true plug-and-play replacement and requires no cutting or permanent modifications. It accepts the original oil-line connections, mounting brackets and factory shroud ducting.

Professional installation is recommended to ensure correct positioning, secure oil-line connections, proper fluid level and adequate clearance around the cooler and surrounding components.

Transmission Oil Cooler Failure Symptoms

• Visible transmission fluid leaks around the cooler, fittings or oil lines
• Fluid residue collecting beneath the front of the vehicle
• Elevated transmission temperatures during demanding driving
• Inconsistent or harsh shifting when the transmission becomes hot
• Corrosion or physical damage caused by road debris
• Reduced cooling efficiency caused by blocked, bent or damaged cooling fins

Important Notes

• Fits 2007–2013 BMW E9X M3 models equipped with the S65 V8 engine.
• Functions as a transmission oil cooler on M3 models equipped with the seven-speed dual-clutch transmission.
• May be used as an auxiliary engine oil cooler on compatible six-speed manual applications.
• Replaces BMW OE cooler part number 17227521376.
• No cutting or modification of the factory mounting area is required.
• Designed to retain the original oil lines, mounting brackets and shroud ducting.
• Transmission fluid, oil lines, seals and additional installation components are not included unless otherwise specified.
• Inspect the factory oil lines, fittings and seals during installation and replace worn or leaking components as required.
• Professional installation and a final leak inspection are recommended.