The 2008 XK with the naturally-aspirated 4.2L V8 (5.0L came in 2010+) is a gorgeous GT that suffers from a catastrophic engine defect: Nikasil cylinder liner failure leading to bore scoring, plus transmission cooling and adaptive transmission learning issues that plague the ZF 6HP26/28 gearbox.
Nikasil Cylinder Bore Scoring / Engine Failure
Common · high severityTypical onset: 60,000-100,000 mi
Symptoms: Cold-start piston slap or rattle that disappears when warm, Loss of compression in one or more cylinders, Blue smoke on cold start, Metal debris in oil, visible on magnetic drain plug, Misfire codes P0300-P0308
Fix: Nikasil liners react with sulfur in low-quality fuel and score; some engines got steel liners as running change. Complete engine rebuild with Nickel Silicon Carbide (Nikasil replacement) sleeves or used/remanufactured engine required. 25-35 hours labor for R&R plus machine work.
Estimated cost: $8,000-15,000
Transmission Oil Cooler Failure / Mixing Coolant and ATF
Common · high severityTypical onset: 70,000-110,000 mi
Symptoms: Milky/strawberry milkshake appearance in transmission fluid, Transmission slipping or erratic shifts, Overheating transmission, Coolant loss with no external leaks, Check engine light with trans temp codes
Fix: Internal cooler in radiator fails, allowing coolant into ATF and destroying clutches. Requires radiator replacement, transmission flush or full rebuild if contamination severe, plus all cooling system fluid replacement. 8-12 hours for cooler/flush; add 18-22 hours if trans needs rebuild.
Estimated cost: $1,500-3,000 (flush scenario); $5,000-7,500 (rebuild scenario)
Transmission Adaptive Learning Loss / Harsh Shifts
Common · medium severitySymptoms: Harsh or delayed 2-3 upshift after battery disconnect, Clunky downshifts when coming to stop, Flare or slip between gears, Transmission 'hunts' between gears on light throttle, Improved behavior after 20-30 drive cycles
Fix: ZF 6-speed loses adaptive values with any power interruption; requires TCM reprogramming with Jaguar IDS/SDD and 30-50 drive cycles for re-learning. Fluid/filter service and valve body cleaning often resolves mechanical component of issue. 3-5 hours for fluid service and adaptation.
Estimated cost: $400-800
Transmission Mounts Collapse
Common · medium severityTypical onset: 50,000-90,000 mi
Symptoms: Clunk when shifting from Park to Drive/Reverse, Vibration at idle in gear, Visible sagging of transmission tailshaft, Driveline shudder under acceleration
Fix: Rubber transmission mount deteriorates, allowing excessive drivetrain movement. Replacement straightforward but requires trans support. 2-3 hours labor.
Estimated cost: $350-600
TPMS Sensor Failure and System Faults
Occasional · low severityTypical onset: 60,000+ mi
Symptoms: TPMS warning light constant or intermittent, One or more sensors not reporting, Fault message on instrument cluster, Sensor batteries dead (10-12 year lifespan)
Fix: Factory TPMS sensors fail or batteries die; requires replacement sensors and reprogramming with IDS. Recall 09V-320 addressed some module software issues. 1-2 hours including reprogramming.
Estimated cost: $300-600
Water Pump and Thermostat Housing Leaks
Occasional · medium severityTypical onset: 80,000-120,000 mi
Symptoms: Coolant seepage from front of engine, Squealing from water pump bearing, Overheating or erratic temp gauge, Coolant smell in cabin or visible drips
Fix: Plastic thermostat housing cracks; water pump weeps from seal. Replace both plus hoses as preventive while in there. 4-6 hours labor.
Estimated cost: $800-1,400
Convertible Top Hydraulic System Leaks (XKR Convertible)
Occasional · low severityTypical onset: 60,000+ mi
Symptoms: Top operates slowly or stops mid-cycle, Hydraulic fluid pooling in trunk, Pump runs excessively, Top will not latch or unlatch
Fix: Hydraulic rams and lines degrade; pump seals fail. Requires system diagnosis, line/ram replacement, fluid refill, and bleeding. 6-10 hours depending on component count.
Estimated cost: $1,200-2,500
Gorgeous and capable, but the Nikasil engine time bomb and transmission cooler design flaw make this a money pit unless you find a late-build car with documented engine replacement or steel liners—buy only with comprehensive pre-purchase inspection by Jaguar specialist.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.