Coolant Expansion Tank - E30 / E36 / Z3 4 cylinder, E34 525i - 17111712835
Replacement for your aged or damaged expansion tank
This high quality replacement coolant expansion tank is used to replace a cracked or leaking coolant tank on the 4 cylinder E30 3 series models (1989, 1990, 1991 318is / 318ic with 16v M42 engine), the E36 4 cylinder (1992-1999 318i, 318is, 318ic, 318ti M42/M44), the E34 525i (M20 and M50 engine variants), as well as the Z3 1.9 liter roadster (M44).
This coolant overflow and expansion tank is made by BEHR, the original equipment manufacturer for BMW, making it the OE choice for fitment and longevity. BEHR is the brand we use on our own BimmerWorld employee, customer and project cars. If your tank hasn't been replaced in a long time, we recommend a replacement part for your aged, cracked, or otherwise deformed coolant expansion tank, as the recommended replacement interval is 100,000 miles.
Please note: On E30 318i/318is models, this tank is only for the later (11/1989 production date and newer) M42 four cylinder models.
Why replace the expansion tank every 100,000 miles? This is because with age, mileage, heat cycling, and environmental conditions, the plastic can become brittle. It may last longer than 100k miles, but you are now running the risk of developing a crank in your tank which could lead to over heating and potentially cause engine damage.
E30 (84-91) > 318i
E30 (84-91) > 318is
E36 (92-99) > 318i M42
E36 (92-99) > 318i M44
E36 (92-99) > 318ic M42
E36 (92-99) > 318ic M44
E36 (92-99) > 318is M42
E36 (92-99) > 318is M44
E34 (89-95) > 525i M20
E34 (89-95) > 525i M50
E36/7 / E36/8 Z3 (96-02) > Z3 1.9