Land Rover Discovery: TD5 Injector Wiring Harness Failure

The plastic-sheathed wiring loom routing across the top of the TD5 engine degrades from heat cycling, causing insulation cracking, chafing against the valve cover, and short circuits at individual injector connectors. Affected cylinders misfire or cut out entirely, often intermittently at first. The fault is so prevalent that a complete loom replacement or uprated aftermarket harness is considered essential preventive maintenance on any unmolested example.

• Intermittent or persistent cylinder misfire
• Rough idle and stumbling under load
• Engine management light with injector fault codes
• One or more cylinders cutting out at idle

1. 1

   Lift the engine cover and trace the injector wiring loom from the ECU plug along the top of the engine to each injector.

2. 2

   Look for cracked or melted insulation, exposed copper, pinch marks where the loom contacts metal, and damaged connector boots.

3. 3

   Pull each injector connector and check the terminals for corrosion.

Parts involved: Fuel injector.

$700 to $1,600 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

• “Has the injector wiring loom been replaced or upgraded to an aftermarket harness?”
• “Any history of misfires, rough running, or injector fault codes?”
• “Has the vehicle had any ECU or injector diagnostic work done?”

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.