BMW E90 Radiator Water Tank

This Radiator Water Tank is an OEM-style replacement part specially engineered for the BMW 3 Series E90 models (2005–2012). It functions as a coolant reservoir, collecting excess coolant during engine operation and feeding it back into the radiator when needed.

Built to meet or exceed OEM specifications, this expansion tank is a direct-fit solution, making installation quick and hassle-free. It’s ideal for BMW owners who want reliable cooling system performance without paying dealership prices.

Installation Tips:

• Always install with a new radiator cap and hose clamps for best results.
• Flush your cooling system before installing the new tank.
• Top off with BMW-approved coolant after installation to prevent overheating or corrosion.

Why Replace Your Radiator Water Tank?

Over time, the expansion tank on your BMW E90 can become brittle, cracked, or discolored, leading to coolant leaks and engine overheating. A failing tank can result in:

• Frequent low coolant warnings
• Poor heating performance
• Increased engine temperatures
• Pressure loss in the cooling system

Replacing it proactively ensures that your BMW’s engine stays cool and efficient—especially under demanding driving conditions.

 Vehicle Compatibility:

Fits the following BMW E90 models:

• BMW 323i (2006–2011)
• BMW 325i (2005–2006)
• BMW 328i (2007–2011)
• BMW 330i (2006)
• BMW 335i (2007–2011)

(Please check your vehicle’s exact engine and production year to confirm compatibility.)

Need Help Choosing the Right Part?

Not sure if this tank fits your specific BMW E90 model? Contact our expert support team, and we’ll help you find the perfect match. We’re here to ensure your replacement is right the first time.

Suitable for the radiator water tank of BMW E90 N45 1.8/2.0 or BMW 3E91/2/3 from 2005 to now or BMW A/M from 2005-2007 vehicle type. Applicable OEM models is : 7521046/7521936/171117542199.

Inlet water tank size is: 476mm X 48mm,

Outlet water tank size is : 476mm X 48mm.