BMW E87 E90 E91 Automatic Gearbox Heat Exchanger Oli Radiator 7551647

BMW E87 E90 E91 Automatic Gearbox Heat Exchanger Oli Radiator is a component from the Oil coolers and lines category, designed to work with the automatic transmission in BMW 3 Series E90 vehicles. It is responsible for stabilizing the transmission oil temperature, which results in smoother transmission operation and reduces the risk of overheating during city and highway driving. This used OEM component is a sensible choice for professional repairs or maintenance of the drivetrain system.

Specifications and technical data

• SKU: 7551647
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7551647
• Substitutable numbers: 17217551647, 7551647
• Gearbox type: Automatic
• Category: Engine Oil Coolers & Lines

Function and role of the transmission oil cooler in the BMW E90

The transmission oil cooler in the BMW E90 is responsible for dissipating excess heat from the oil circulating in the automatic transmission. Maintaining a stable temperature of the lubricating medium:

• reduces transmission oil degradation under high loads,
• supports smooth gear shifting,
• decreases the risk of slipping and jerking during gear changes,
• positively affects the durability of friction elements and seals.

For the user, this means more predictable automatic transmission behavior, especially under intensive use, frequent stop-and-go driving, and driving at higher speeds.

Designed for automatic transmission

The presented cooler is designed for use with an automatic transmission, which is important both when selecting parts and when planning the scope of repairs. Automatic transmissions generate significantly higher thermal loads than manual ones, which is why a functional oil cooling system is crucial for:

• maintaining stable transmission operating parameters,
• preserving proper oil viscosity across a wide temperature range,
• limiting costly failures resulting from overheating.

Choosing a cooler dedicated to an automatic transmission allows for maintaining the factory characteristics of the gearbox and facilitates installation in the original mounting points.

Characteristics of the used OEM component

The offered BMW E87 E90 E91 Automatic Gearbox Heat Exchanger Oli Radiator is a used original part, sourced from dismantling. In practice, this means:

• preservation of factory geometry of connections and oil ports,
• compatibility with original lines from the Oil coolers and lines group,
• easier installation without the need for system adaptation.

A used OEM component is often chosen as a technically sensible alternative to new replacements, especially for repairs where compliance with factory specifications and predictable long-term system behavior are important.

The importance of a functional cooler for system durability

A functional transmission oil cooler has a direct impact on the lifespan of the automatic transmission and driving comfort. Replacing a worn or leaking component with a functional one allows you to:

• limit the risk of oil overheating and pressure drops in the system,
• reduce the possibility of errors related to transmission temperature,
• maintain stable operating conditions for the mechatronics and clutch packs.

If your BMW shows symptoms of overheating, degraded gear shifting quality, or signs of leaks in the cooler area, replacing this component is one of the essential service steps.

Related components and further knowledge

If you are planning a comprehensive repair or upgrade of the cooling system area in your BMW and need other elements from the same group, such as additional oil coolers, oil lines, or connectors, check the available parts in the BMW oil coolers and lines category.

To better understand the impact of the cooling system on the durability of the powertrain and accessories, it is worth reading the guide Engine cooling system – overheating, repair, and used radiators, which discusses practical aspects of diagnostics and selecting used cooling components.

If you are interested in a broader context of transmission operation and maintenance, the material Gearbox: manual, automatic, or DSG – typical faults and a guide to buying a used gearbox may also be helpful, describing the characteristics of different types of transmissions and the most common problems encountered in workshop practice.