Nissens 996361 Engine Coolant Reservoir

Nissens 996361 Engine Coolant Reservoir

The Nissens 996361 engine coolant reservoir is a pressurized expansion tank built for select BMW applications. It combines an OE-matching plastic construction with a cap and level sensor already included, making it a direct replacement option for cooling system service on 1999-2003 BMW 528i and 525i models.

Key Features

• Plastic coolant reservoir with a 1.30L capacity
• Pressurized design for cooling system expansion and pressure control
• Cap included for a complete reservoir assembly
• Level sensor included for coolant level monitoring
• OE-matching plastic construction with reinforced fittings
• High-durability welding for secure tank seams

Detailed Description

Nissens 996361 is an aftermarket engine coolant reservoir engineered as an expansion tank replacement for BMW cooling systems. It is manufactured with OE-matching plastics and reinforced connection points to support a secure fit at the hose and sensor interfaces. The reservoir is pressure-rated, includes the cap, and comes with a pre-mounted level sensor, which helps simplify replacement on vehicles that use electronic coolant level monitoring. This part cross-references Four Seasons 36403 for the same application.

Compatible With 1999-2000 BMW 528i and 2001-2003 BMW 525i cooling system service, this reservoir is intended for drivers replacing a cracked tank, leaking seam, or failed level sensor assembly. The Nissens 996361 part number is also useful when matching an OE-style expansion tank by application and connector layout.

Common Issues This Part Can Address

• Coolant loss from a cracked or split reservoir
• Pressure loss caused by a damaged expansion tank seam
• Low coolant warnings from a faulty level sensor
• Cap-related seepage or pressure retention problems
• Cooling system service needs on aging BMW 525i and 528i models

Installation Notes and Tips

Verify hose routing, sensor connector style, and mounting points before installation. Transfer any vehicle-specific hoses or brackets not supplied with the reservoir, and inspect the cooling system for related wear such as brittle hoses or a weakened thermostat housing. After installation, refill and bleed the cooling system according to BMW service procedures to remove trapped air.

Quality Assurance

Nissens tests the reservoir and internal components for fit and reliable operation. The tank is built with reinforced fittings and durable welded seams to support consistent cooling system performance in normal service.