BMW Coolant Expansion Tanks

Our Turner Motorsport's full aluminum expansion tank was designed and engineered in house to help with the weak point in your N52/N54 cooling system. The coolant expansion tank goes through heat cycles over and over again from regular driving, it is important that your expansion tank is doing its job to retain coolant to keep your engine operating temperatures down and keep your engine bay clean. Not only is this a major upgrade but also a great maintenance item to replace. Our expansion tank was designed to fit the OEM hoses for an easy install and comes with all the upgraded items you will need for a clean install

If your BMW needs a new expansion tank, make sure this is the last expansion tank you ever need to buy. Our coolant expansion tank has a full aluminum construction and wrinkle black powder coat for durability. Expansion tank kit comes with all the accessories you need to replace your expansion tank once, and never have to worry about it again.

Product Features:

Maintains stock coolant capacity and expansion volume
Designed to maintain OE coolant elevation, preventing air pockets
Baffled tank ensures that air pockets cannot be introduced during aggressive driving and provides accurate coolant level reading
Carefully designed bleed passage prevents the introduction of air as the engine cools
Turner engraved internal fill level
TIG welded 5052 aluminum construction
All bungs are machined to fit factory hose ends
Kit contents:

Turner Aluminum Expansion Tank
Coolant level sensor
Expansion tank cap
Heavy duty bleeder screw
Flared coolant pressure release line
Hardware for installation

Upgraded or replacement silicone heater hose for our N54 expansion tank relocation kits.

60" silicone performance coolant hose featuring a molded 90-degree bend for installs with space constraints.

Features and benefits:

Constructed of 4-Ply reinforced silicone for improved durability over the failure-prone rubber hoses.
Reduced thermal conductivity
Improved resistance to ozone and UV degradation for improved performance and durability.
Turner branded

BMW N47 N55 Expansion Tank from Turner Motorsport is a high-quality replacement designed to address issues with cracked or damaged coolant expansion tanks. Engineered for durability and performance, this expansion tank ensures reliable cooling system function.

• Durable Construction: Built to withstand high temperatures and pressure, ensuring long-term reliability.
• Direct Replacement: Engineered as a precise fit for BMW N47 and N55 engines, making installation straightforward and hassle-free.
• Enhanced Cooling Efficiency: Maintains optimal coolant levels and pressure for effective engine cooling.
• High-Quality Materials: Manufactured from premium materials to resist cracking and leaks.

Coolant level sensor for most E30, E32, and E34 cars. Fits E30 M3 and all E30 325's; E32 735, 740, and 750; and E34 530, 535, 540, and M5. 

Since the late 1800’s Febi has been fabricating replacement metal parts. This history is self evident in the quality and vast amount of applications they service. With more than 34,000 repair solutions for cars and commercial vehicles you can be sure Febi has you covered.

This item fits the following BMWs:
1987-1991 E30 BMW 318i 318is 318ic 325e 325es 325i 325is 325ic 325xi M3
1989-1995 E34 BMW 530i 535i 540i M5
1987-1989 E24 BMW 635csi M6
1988-1994 E32 BMW 735i 735il 740i 740il 750il

We have found that the expansion tanks should be replaced based on age as well as condition. Expansion tanks seem to have a lifespan of less than six years before they show signs of fatigue and wear. Pre-emptively replacing the expansion tank as part of an overall maintenance plan can prevent you from getting stranded from a sudden failure later on.

Other items to consider replacing at the same time are the radiator cap, coolant level sensor, lower radiator hose, coolant temp sensor, and the hose clamps. If your car has an automatic transmission you should also replace the oil cooler thermostat in the radiator frame, which is a common source for leaks.

As a leading source of high-performance BMW parts and accessories since 1993, we at Turner Motorsport are honored to be the go-to supplier for tens of thousands of enthusiasts the world over. With over two decades of parts, service, and racing experience under our belt, we provide only quality performance and replacement parts. All of our performance parts are those we would (and do!) install and run on our own cars, as well as replacement parts that are Genuine BMW or from OEM manufacturers. We only offer parts we know you can trust to perform!

• Features a billet radiator-style neck for enhanced durability
• Resolves expansion tank issues with a solid, built-in mount
• Eliminates worries about separating and leaking plastic tanks
• Perfectly complements Canton Racing 77-272 MINI power steering tank

This radiator expansion tank is used on E53 X5 4.4i and 4.6is with M62 engine, and Z3 2.3 2.5i 2.8 3.0i from 1999-2002. It is a common failure item as the plastic weakens over time and stress cracks will lead to coolant leaks. We have found that the expansion tanks should be replaced based on age as well as condition. Expansion tanks seem to have a lifespan of less than six years before they show signs of fatigue and wear. Pre-emptively replacing the expansion tank as part of an overall maintenance plan can prevent you from getting stranded from a sudden failure later on. This is the OEM Behr part - not an aftermarket. We have found that the aftermarket coolant reservoirs fail easier than the OEM Behr part. Hailing from Stuttgart, Mahle-Behr specializes in automotive cooling systems. From air conditioning to engine cooling M-B has you covered with OE-quality replacement parts.

Hailing from Stuttgart, Mahle-Behr specializes in automotive cooling systems. From air conditioning to engine cooling M-B has you covered with OE-quality replacement parts.

This item fits the following BMWs:
2000-2003 X5 BMW X5 4.4i X5 4.6is
1999-2002 Z3 BMW Z3 2.3 2.5i 2.8 3.0i

BMW Silver Auxiliary Coolant Reservoir Cap is the perfect upgrade for BMW owners looking to enhance both the aesthetics and functionality of their engine bay. Unlike generic aftermarket caps that overlook critical pressure regulation, this precision-engineered cap retains the OEM pressure release functionality, ensuring safe and reliable coolant system performance.

Crafted from high-quality billet aluminum, this reservoir cap offers superior durability and resistance to heat and fluids, preventing warping or degradation over time. Unlike adhesive-based cap covers that can loosen or fall off, this cap is a direct replacement for the factory component, providing a secure, high-performance solution.

• OEM pressure release functionality – Maintains proper system regulation for optimal coolant performance
• Premium billet aluminum construction – Offers enhanced durability and longevity
• Direct replacement design – Secure fit without adhesives or modifications
• Resistant to heat and fluids – Ensures long-lasting reliability in extreme conditions
• Performance-inspired look – Adds a sleek, high-end appearance to your engine bay
• Upgraded durability – Prevents cracking, leaks, and premature wear

Upgrade your BMW’s cooling system with the BMW Silver Auxiliary Coolant Reservoir Cap, blending performance, reliability, and premium styling.

This high quality Hella/BEHR brand expansion tank is used on M42, M44, M50, M52, engines, and is a common failure item on all E36 3 series with 4 cylinder engines (318i/is/ti/ic) 1990-1999, Z3 with 1.9 liter and E34 525i from 1989-1995. Hella/BEHR was the original equipment supplier to BMW, so you know the Hella/BEHR made expansion tank will be the highest quality available. Be leary of competitors selling this part for less -- is it a Hella/BEHR? Probably not. We only carry the Hella/BEHR brand expansion tank as it is the only one we use in our own BMWs.

Hella is a premium manufacturer that supplies automotive parts to numerous car brands across the world. Everything from electrical to mechanical genuine parts have been made and supplied directly to BMW before the vehicles ever leave the production floor. Their high quality, long lasting parts have made them a trusted brand chosen to help keep your BMW on the road for many years to come.

As a leading source of high performance BMW parts and accessories since 1993, we at Turner Motorsport are honored to be the go-to supplier for tens of thousands of enthusiasts the world over. With over two decades of parts, service, and racing experience under our belt, we provide only quality performance and replacement parts.  All of our performance parts are those we would (and do!) install and run on our own cars, as well as replacement parts that are Genuine BMW or from OEM manufacturers. We only offer parts we know you can trust to perform!

This item fits the following BMWs:
1990-1991 E30 BMW 318i 318is 318ic
1992-1998 E36 BMW 318i 318is 318ti 318ic
1989-1995 E34 BMW 525i
1996-1998 Z3 BMW Z3 1.9