IsItAGoodCar
Reliability Guide

Common Problems with the
2004 Land Rover Discovery 2 (L318)

We've identified 3 known issues that can affect the 2004 Land Rover Discovery 2 (L318). 2 of these are serious faults that could be expensive to repair.

3
Known Issues
2
Serious
1
Moderate
0
Minor

All Known Issues

TD5 Injector Harness Oil Migration

SeriousEngine

Oil seeps along the injector wiring harness into the ECU red plug connector, causing rough running, misfires and potential ECU damage.

Est. Repair Cost: £100–£500
Warning Signs:

Rough idle, Misfires, Hard starting, Engine cutting out

What to Inspect:
  • Oil in ECU red plug
  • Injector harness condition
  • Injector seal condition
Verified by IsItAGoodCar Research Team

Air Suspension and ACE System Failures

SeriousSuspension & Chassis

Self-levelling suspension (SLS) air bags perish and compressors fail. The ACE system leaks from corroded pipes, causing handling issues and expensive repairs.

Est. Repair Cost: £400–£2,000
Warning Signs:

Vehicle sagging, ACE warning light, Fluid leaks underneath, Compressor running constantly

What to Inspect:
  • Air bag condition
  • ACE pipe condition
  • Compressor operation
  • Ride height sensors
Verified by IsItAGoodCar Research Team

Three Amigos (ABS/TC/ HDC Warnings)

ModerateElectrics & Electronics

The ABS, Traction Control, and Hill Descent Control warning lights illuminate together. Usually caused by ABS sensor failures but can indicate more expensive 4WD system issues.

Est. Repair Cost: £100–£800
Warning Signs:

Three warning lights on together, Loss of traction control, HDC inoperative

What to Inspect:
  • ABS sensor condition
  • Fault codes
  • Brake pedal switch
Verified by IsItAGoodCar Research Team

Buying Tips for 2004 Land Rover Discovery 2 (L318)

  • ✓On TD5 models, check for oil in the injector wiring loom - a very common and cheap fix if caught early
  • ✓The head gasket is a known failure on early TD5s with plastic dowels; look for metal dowel replacements
  • ✓ACE (Active Cornering Enhancement) pipes leak and are expensive; some owners delete the system entirely
  • ✓Check the chassis carefully for rot, especially around towbar mounting points
2003
Check a 2004 Land Rover Discovery 2 (L318) by Registration