Spark Plugs 4.0L (Discovery 3)

Removing

1. Disconnect a wire of weight from the accumulator. For more information refer to Specification.

2. Remove the engine cover. For more information refer to Engine Cover - 4.0L (12.30.50)

3.

CAUTION: When pulling the spark plug wire, twist the wire boot to avoid possible damage to the spark plug wire.

NOTE: Note the position in which the part was installed.

Disconnect high voltage electrical connectors (NT).

4.

WARNING: Wear eye protection.

NOTE: Use compressed air to remove all foreign material from the spark plug recesses.

Clean the area around the spark plugs.

5. Turn out spark plugs.

Installation

1.

ATTENTION: Before installing new copper spark plugs, check the electrode gaps, they should be 1.4 mm, adjust if necessary. The gap of existing platinum or copper spark plugs must not be changed during service work; if the gap is incorrect, new spark plugs must be installed.

NOTE: Do not apply lubricant to the threads.

Screw in the spark plugs.

• Check spark plug gap (see specifications).
• Tighten spark plugs (tightening torque 18 Nm).

2.

CAUTION: Install the spark plug wires according to the position noted during removal.

Don't cross wires. Connect the HT electrical connectors. Apply silicone grease to the inside of the spark plug housing.

3. Install the engine cover. For more information refer to Engine Cover - 4.0L (12.30.50)

4. Connect a wire of weight to the storage battery. For more information refer to Specification.