IsItAGoodCar
Reliability Guide

Common Problems with the
2001 Jaguar XJ8 / XJR (X308)

We've identified 3 known issues that can affect the 2001 Jaguar XJ8 / XJR (X308). 3 of these are serious faults that could be expensive to repair.

3
Known Issues
3
Serious
0
Moderate
0
Minor

All Known Issues

Primary and Secondary Timing Chain Tensioner Cracking

SeriousEngine

Early AJ-V8 engines fitted to the X308 were assembled with plastic-bodied primary and secondary timing chain tensioners. Over years of thermal stress and exposure to combustion byproducts, the plastic casing becomes brittle and fractures. When the plastic guide shoe delaminates, the secondary chain slips on the camshaft sprocket, throwing valve timing out of synchronization and causing the valves to strike the pistons, typically requiring a complete cylinder head rebuild or replacement engine.

Est. Repair Cost: £750–£1,400
Warning Signs:

Prominent metallic ticking or rattling from the front timing cover during the first five seconds of a cold start, Rough idle with misfire fault codes stored for banks 1 and 2, Sudden total engine failure with rapid cranking speed and zero compression

What to Inspect:
  • Inspect service records for specialist invoices detailing third-generation metal-bodied tensioner replacement
  • Ask the seller if the cam covers have been removed to inspect the colour of the upper tensioners (metal body is silver, plastic is orange/brown)
  • Listen carefully for mechanical slap around the front of the cylinder heads during a dead-cold startup
Verified by IsItAGoodCar Research TeamUpdated

ZF 5HP24 Forward Clutch A-Drum Failure

SeriousGearbox & Transmission

The ZF 5HP24 five-speed automatic transmission fitted to naturally aspirated 3.2 and 4.0 X308 models suffers from a known structural design defect in the forward clutch A-drum. Excessive hydraulic line pressure pulses caused by a worn main pressure regulator valve fracture the snap-ring retaining lip on the aluminium drum. Once the lip shears, the forward clutch pack fails to compress, completely eliminating forward gears while reverse gear remains functional.

Est. Repair Cost: £1,200–£2,200
Warning Signs:

Sudden free-revving with total loss of forward drive when pulling away from a standstill, Gearbox Fault warning illuminated on the instrument cluster with transmission limp-home mode, Reverse gear operates normally but selecting Drive produces neutral-like engine revving

What to Inspect:
  • Engage Drive from a standstill and verify crisp, immediate take-up without hesitation or rev flaring
  • Check automatic transmission fluid level and examine for dark burnt fluid or metallic clutch particulate
  • Inquire whether an uprated heavy-duty steel-reinforced A-drum has been installed during a past transmission overhaul
Verified by IsItAGoodCar Research TeamUpdated

Water Pump Plastic Impeller Delamination & Overheating

SeriousCooling System

Early AJ-V8 water pumps were manufactured with black plastic impellers pressed onto the metal drive shaft. Heat cycling and chemical degradation cause the plastic impeller blades to soften, fracture, or spin freely on the shaft without circulating coolant. Because coolant flow halts while the belt pulley turns normally, the engine rapidly overheats, risking warped aluminium cylinder heads and blown head gaskets before the dashboard temperature gauge alerts the driver.

Est. Repair Cost: £200–£500
Warning Signs:

Sudden temperature gauge needle spike into the red zone under moderate acceleration or town driving, Cabin heater blows stone-cold air despite the engine running at normal or elevated operating temperature, Coolant overflow ejected past the expansion tank pressure cap with boiling gurgles in the cooling hoses

What to Inspect:
  • Check service history for replacement of the water pump with an updated metal-impeller unit
  • Inspect the water pump pulley area for play, bearing squeal, or dried white/pink coolant traces
  • Verify cabin heater output at idle; lack of hot air indicates stagnant coolant flow from a broken impeller
Verified by IsItAGoodCar Research TeamUpdated

Buying Tips for 2001 Jaguar XJ8 / XJR (X308)

  • Confirm through invoices that the upper secondary timing chain tensioners have been replaced with third-generation metal components to prevent sudden catastrophic engine failure.
  • On naturally aspirated 3.2 and 4.0 models with the ZF 5HP24 gearbox, verify that forward drive engages immediately from cold without rev flaring or transmission limp-home warnings.
  • Check engine temperature behaviour carefully; original plastic water pump impellers can disintegrate without warning, causing sudden severe overheating and warped cylinder heads.
  • Inspect front lower wishbone ball joints, anti-roll bar drop links, and rear subframe bushes, which wear rapidly under the weight of the V8 luxury chassis.
  • Test every electrical circuit including the central locking, electric memory steering column rake motors, and dual-zone climate control blend flaps for smooth operation.
20002002
Check a 2001 Jaguar XJ8 / XJR (X308) by Registration