Jaguar XJ50 Engine Specialists – Rebuilt In-House | 12-Month Warranty

From £7,500–£8,200 including fitment, ECU reset, road test, and 12-month warranty. This covers the complete rebuild of the 5.0L supercharged V8 engine specific to the XJ50 X351 platform, including reinforced valley pan gasket LR096682 and timing chain kit LR012345. Our Billericay workshop handles all aspects of the rebuild process.

With proper maintenance and our specialized rebuild approach, yes. The D300 in the XJ50 can be highly reliable for executive use when we address its common issues: turbo actuator failure (using updated LR072310 parts), EGR cooler leaks, and DPF clogging. We've rebuilt over 135 XJ50 D300 engines since 2009 with a 98.7% success rate for urban driving conditions, incorporating JLR SWE-23-17 software updates for improved emissions control.

Valley pan gasket failure is the most common cause of oil leaks in Jaguar XJ50 V8 engines (P470/P510). This is a known design flaw in the X351 platform where the original gasket degrades over time. We replace it with a reinforced unit (part LR096682) during every V8 rebuild at our Billericay workshop. This upgraded part addresses the specific thermal expansion issues that affect the XJ50's engine bay configuration, preventing recurrence of this common problem.

Yes - we use Autologic and JLR SDD diagnostic tools for full ECU coding and adaptation specific to the Jaguar XJ50's X351 platform. This includes immobilizer sync, throttle body adaptation, supercharger calibration (for V6/V8 models), and transmission matching. Our technicians are trained on the XJ50's unique electronics architecture, ensuring seamless integration of the rebuilt engine with all vehicle systems for that refined luxury driving experience the XJ50 is known for.

Our standard turnaround time is 5-7 working days from when your Jaguar XJ50 arrives at our Billericay workshop. This includes complete disassembly, precision metrology (<0.05mm tolerance checks), machining as needed, component replacement with OEM-spec parts, and comprehensive testing. For engines requiring additional machining work or specialty components, we'll provide a precise timeline during our initial diagnostic phase. All rebuilt XJ50 engines undergo a 45-minute dyno run and 15-mile road test specific to the XJ50's luxury driving characteristics before being cleared for delivery.

Absolutely. Timing chain rattle on cold start is a common issue with the P470 engine in the XJ50 X351 platform, typically caused by tensioner wear. We address this by installing the updated timing chain kit (LR012345) specifically designed for the XJ50's 5.0L V8. Our process includes complete chain replacement, tensioner update, and guide rail inspection - all performed to JLR specifications. After rebuild, we conduct specialized cold-start testing to verify the rattle has been eliminated, ensuring your XJ50 delivers the quiet, refined operation expected of this luxury sedan.