X4XZ Coolant Reservoir Tank for Ford Fiesta 2011-2019 — 603-381 Direct-Fit Overflow Tank with Cap, OE-Equivalent

The X4XZ 603-381 coolant reservoir tank with cap is a direct-fit replacement overflow tank engineered for 2011–2019 Ford Fiesta 1.0L and 1.6L engines to restore proper coolant expansion and recovery.

If your Fiesta is losing coolant, running hotter than usual, or showing coolant level warnings, a worn or cracked overflow tank can be the culprit. The X4XZ 603-381 (OE-equivalent) is molded from durable plastics to match original dimensions and mounting points, making it a straightforward swap for the factory part numbers listed by Ford.

How does this tank maintain proper engine cooling?

The reservoir provides a controlled place for excess coolant to expand into when the engine heats up and then returns coolant to the radiator during cooldown. That pressure-managed exchange helps stabilize coolant levels, minimize air ingress, and supports consistent heater performance without interfering with the sealed cooling system.

• Captures expanding fluid during thermal cycles to prevent radiator overflow.
• Returns coolant to the system as temperature drops to preserve level stability.
• Helps reduce the risk of air pockets and associated hot spots in the engine.

Will this unit fit my Ford Fiesta model and how do I confirm compatibility?

The X4XZ reservoir is manufactured to match OE# 603-381 and replaces several Ford part numbers such as 8V218K218AB/BE and BE8Z-8A080-A. Always cross-check your vehicle’s part number or use the online fitment tool to confirm fitment before ordering.

• Fits 2011–2019 Ford Fiesta 1.0L and 1.6L applications when matching OE numbers.
• Compare printed part numbers or use the retailer vehicle-fit filter for verification.
• Professional inspection recommended if aftermarket modifications exist.

What are the build quality and installation notes?

Constructed from high-grade plastic, the tank is designed to meet or exceed original equipment form, fit and function standards. It ships with the filler cap and is sold as a single complete unit; however, installation instructions are not included, so have basic tools or a mechanic ready.

• Made from durable materials to resist heat and vibration over service life.
• Includes the cap; hoses and clamps typically reuse from the vehicle unless damaged.
• Professional installation recommended; ensure proper torque and hose connections.

What comes in the package and what support is available?

Each kit contains one coolant overflow reservoir tank and cap, ready for installation. X4XZ provides customer support and a one-year product service policy to address fitment or quality concerns after purchase.

• Package: 1 x coolant overflow reservoir tank with cap.
• No printed manual included; seek a professional installer for precise mounting.
• 24-hour customer service and one-year product coverage from X4XZ.

Who is this for: The X4XZ 603-381 reservoir tank is intended for Ford Fiesta owners and independent mechanics needing a reliable replacement for a cracked, leaking, or missing overflow tank on 2011–2019 1.0L and 1.6L engines. It's suited to drivers wanting an OE-equivalent part that restores coolant management, and to repair shops seeking a cost-effective, ready-to-install unit that meets factory fitment standards.