IsItAGoodCar
Reliability Guide

Common Problems with the
2003 Jaguar XK8 / XKR (X100)

We've identified 1 known issue that can affect the 2003 Jaguar XK8 / XKR (X100). 1 of these are serious faults that could be expensive to repair.

1
Known Issues
1
Serious
0
Moderate
0
Minor

All Known Issues

Rear Suspension Subframe and Chassis Sill Corrosion

SeriousBodywork & Rust

The X100 chassis traps road mud, wet salt spray, and moisture behind the full-length plastic sill covers, inside the rear wheel arches, and across the fabricated rear subframe mounting points. Structural steel inner sills and front footwell floor outriggers corrode from the inside out. By the time bubbling paint appears externally, extensive structural welding is required to meet UK MOT requirements.

Est. Repair Cost: £600–£2,000
Warning Signs:

Crunching or creaking sound when placing a workshop trolley jack beneath factory jacking points, Bubbling paint along lower front wheel arch edges and forward of the rear wheels, UK MOT failure advisory for structural corrosion within 30cm of safety mounting points

What to Inspect:
  • Use a high-intensity inspection torch to probe inner sills and seat belt anchorage floor sections
  • Inspect the rear suspension A-frame mounting plates and crossmember bushes for flaky rust
  • Examine past UK MOT history for repeat advisories regarding underbody and floor corrosion
Verified by IsItAGoodCar Research TeamUpdated

Buying Tips for 2003 Jaguar XK8 / XKR (X100)

  • Demand documented proof that early 4.0-litre AJ26/AJ27 engines have had their fragile plastic secondary timing chain tensioners upgraded to third-generation metal-bodied units.
  • Inspect the structural sills and floorpans thoroughly; corrosion hidden behind the plastic sill kick-plates and around the rear subframe mounts is the leading cause of MOT failure.
  • On convertible models, check the hydraulic hood mechanism for slow operation, green fluid leaks beneath the rear seat, or hydraulic ram hose degradation.
  • Verify automatic transmission servicing; the five-speed ZF 5HP24 (and Mercedes 722.6 on early XKR) requires fresh fluid and filter changes every 50,000 miles despite original sealed-for-life claims.
  • Test the condition of the front suspension wishbone bushes and CATS adaptive dampers; heavy V8 front-end weight rapidly wears lower ball joints and causes uneven front tyre wear.
Check a 2003 Jaguar XK8 / XKR (X100) by Registration