Td5 oil in loom – injector looms, seals & fixes

The classic Td5 oil in loom problem is caused by engine oil creeping along the injector wiring harness inside the rocker cover. Over time that oil reaches the ECU red plug and starts to interfere with the injector signals, leading to rough running, misfires, poor starting and random fault codes.

This page pulls together the key parts you need to fix it properly on Defender Td5 and Discovery 2 Td5:

• Td5 injector wiring looms – AMR6103 is the loom we use for practical repairs, while OE-quality AMR6103G is the higher-tier option with 2-year warranty
• Td5 rocker cover gaskets – worth replacing if the gasket is old, flattened or leaking
• Brake, clutch & electrical cleaner – ideal for flushing oil out of ECU plugs and the external engine harness

Typical Td5 oil in loom symptoms

• Uneven idle, hesitation or misfires that come and go
• Hard starting or cutting out, especially when hot
• Oil visible in the injector loom plug or ECU red connector

Recommended repair

1. Replace the injector wiring loom
2. Clean the ECU plug and external engine loom with electrical cleaner
3. Replace the rocker cover gasket if needed
4. Repeated flushing with electrical cleaner is normally required