Performance Water Pump & Thermostat Kit for Jaguar XJ (2013-2019) 3.0L

Heavy-Duty Water Pump & Thermostat Cooling Overhaul Kit for 2013-2019 Jaguar XJ (X351)

What it Does: The Performance Water Pump & Thermostat Kit replaces failure-prone plastic cooling conduits and worn pump components on the 2013-2019 Jaguar XJ to eliminate catastrophic coolant loss and maintain critical engine operating temperatures.

The Stock Jaguar XJ Cooling System Failure Points

The AJ126 3.0L supercharged V6 under the hood of the X351 chassis generates intense underhood thermal loads. Factory cooling systems rely on multi-piece molded plastic coolant crossover pipes routed beneath the supercharger. Over continuous heat cycles, these plastic passages degrade, embrittle, and rupture along their ultrasonic welded seams. Compounding this risk, factory water pump shaft seals are prone to weeping, and brittle plastic bleeder screws frequently shear during routine service, causing rapid loss of cooling pressure and catastrophic cylinder head warping.

The Engineering Solution

This comprehensive cooling overhaul kit permanently resolves OEM vulnerabilities by replacing brittle plastic cooling bridges with rigid aluminum coolant crossover pipes engineered to withstand severe thermal expansion without cracking. The direct-fit replacement water pump features reinforced bearing assemblies and upgraded shaft seals to handle continuous high-RPM water jacket pressures. A brand-new thermostat assembly with an integrated sensor ensures immediate, accurate thermal regulation, while durable copper bleeder hardware and copper hose fittings replace brittle OEM plastic connectors for permanent, leak-free reliability.

What's Included

• 1x Water Pump
• 1x Thermostat with Integrated Temperature Sensor
• 1x Upgraded Aluminum Coolant Crossover Pipe Assembly
• 1x Thermostat Outlet Hose with Copper Fittings
• 1x Copper Bleeder Screw & Crossover Plug
• 1x Heater Outlet Hose

Technical Specifications

Compatibility

• 2013-2019 Jaguar XJ 3.0L V6 Supercharged (X351)
• Fits AJ126 3.0L Supercharged V6 and select AJ133 5.0L Supercharged V8 applications matching listed OEM references
• Does not fit naturally aspirated engine variants

Frequently Asked Questions & Fitment Warnings

Does this fit the X351 XJ?

Yes, this is a direct fit for the 2013-2019 Jaguar XJ equipped with the AJ126 3.0L Supercharged V6 engine. This kit does not fit naturally aspirated engines; always verify that your original part numbers match before installation.

Is vacuum-assisted coolant bleeding required after installation?

Yes, due to the complex cooling jacket routing beneath the supercharger on the AJ126, a vacuum refill and thorough cooling system bleed are required to prevent trapped air pockets from causing localized hot spots.

The Jaguar Standard

Engineered to exact European performance tolerances, this upgraded cooling kit delivers absolute thermal stability, zero check-engine warnings, and complete peace of mind on the highway or in heavy traffic.