Cobb Subaru 15-21 WRX/STI Coolant Overflow Tank

COBB Tuning Performance Parts deliver proven power gains with factory-like drivability backed by an "Engineered Performance" approach trusted by enthusiasts, pro tuners, and performance shops worldwide. Founded in 1999 and now headquartered in Austin, Texas, COBB designs, engineers, tests, and supports its products in-house to ensure reliable results across today's most popular performance platforms. Shop the full lineup of COBB Tuning performance parts at Black Ops Auto Works, including ECU tuning solutions, bolt-on upgrades, and staged power packages built to work together for predictable, repeatable performance. COBB ECU Tuning & Accessport The COBB Accessport is one of the most trusted ECU tuning devices in the industry. It enables safe ECU flashing, live data monitoring, diagnostics (read/clear codes), and tuning management helping drivers unlock stronger throttle response, improved drivability, and dependable horsepower and torque gains when paired with the right supportin...

Coolant reservoirs, also called expansion tanks or overflow bottles, maintain a pressurized coolant supply that the radiator draws from as the cooling system cools down after engine-off. A cracked or leaking reservoir causes coolant loss and eventual overheating, while an upgraded billet or aluminum tank improves appearance and durability in performance engine bays.Popular UpgradesAluminum and billet coolant expansion tanks for LS and LT engine swaps and popular domestic performance vehicles are the most popular upgrades, providing a clean look and superior durability compared to factory plastic bottles that crack from heat cycling. Universal inline overflow tanks made from polished aluminum or anodized billet are popular on custom engine bays where the stock location has been eliminated. Direct-fit OEM-style replacement tanks restore coolant system function on high-mileage vehicles where the factory tank has cracked or the cap seat has deteriorated.How do I know if my coolant reser...

Shop performance cooling parts at Black Ops Auto Works for premium radiators, thermostat housings, thermostats, coolant reservoirs, expansion tanks, radiator hoses, oil coolers, transmission coolers, fans and shrouds, water pumps, and thermal management upgrades for street, track, towing, diesel, and high-horsepower builds. Whether you are trying to control engine temps, improve reliability, or support demanding performance use, this collection is built around proven cooling-system upgrades for serious enthusiasts. Shop Cooling Parts by Category Browse automotive cooling system components across key product categories, including: Radiators Coolant reservoirs and expansion tanks Thermostat housings and thermostats Radiator hose kits and silicone coolant hoses Oil coolers and oil cooler accessories Transmission coolers Coolant bypass kits and coolant filters Fans and shrouds Radiator caps Water pumps Radiator shrouds, radiator stays, and cooling plates Thermal wrap, thermal tape, an...

Shop engine parts, oil catch cans, engine cooling upgrades, thermostats, thermostat housings, radiators, coolant accessories, supercharger pulleys, idler pulleys, tensioner pulleys, throttle bodies, engine covers, fuse box covers, cap covers, valve covers, oil system parts, ignition parts, sensors, gaskets, fuel delivery parts, and engine bay dress-up accessories at Black Ops Auto Works. This collection is built for performance vehicles, trucks, SUVs, muscle cars, boosted builds, HEMI platforms, Hellcat builds, Trackhawk SUVs, RAM TRX trucks, LS-powered builds, and high-horsepower street or track applications. Whether you are improving oil control, reducing heat soak, upgrading cooling, supporting higher boost, cleaning up the engine bay, replacing worn engine components, or preparing a street car for harder driving, this collection helps you shop engine parts by brand, category, vehicle platform, and performance goal. Shop Engine Parts by Category Browse engine upgrades and replace...