Parts for your 1998 Mitsubishi Pajero-Knock sensor

1998 Mitsubishi Pajero Knock Sensor – What’s Fitted and What To Do

Based on factory information, the 1998 Mitsubishi Pajero may or may not have a knock sensor depending on the engine. The petrol V6 models (6G72 3.0L and 6G74 3.5L) are fitted with a knock sensor used by the ECU to trim ignition timing. In contrast, the 2.8L turbo-diesel (4M40) does not use a knock sensor, as compression-ignition engines don’t suffer spark knock and manage combustion using fuel timing and boost control instead. This split is supported by the Mitsubishi Pajero/Montero Factory Service Manual (1997–1999: 6G7 Engine Electrical, “Knock Sensor (KS)”), Mitsubishi ASA parts catalog listings for 6G7 knock sensor components, and the 4M40 engine manual, which contains no KS circuit.

For petrol V6 owners, the knock sensor is an unsung hero. It listens for pinging (detonation) and lets the ECU fine-tune timing on the fly, so the engine runs smoothly on varied fuel quality and under heavy load. On the 6G72/6G74 it’s mounted on the engine block within the V of the V6, beneath the upper intake manifold. If it goes crook, the ECU typically pulls timing as a safety move, which can make the Paj feel sluggish, use more fuel, and light the check engine lamp with codes like P0325/P0330.

Replacement is straightforward workshop fare but usually requires removing the upper intake plenum for access. The key is to use a quality sensor, clean the mating surface on the block, and tighten to the workshop manual spec so it can “hear” properly. Don’t overtighten, that can deaden the sensor or crack it. While you’re there, inspect the sub-loom and connector — heat under the manifold can make the wiring brittle, and a cracked plug can mimic a failed sensor.

As part of normal servicing, a quick once-over goes a long way:

• Look for oil or coolant leaks under the manifold area that could contaminate the sensor or plug.
• Check the harness routing and tape, keep it away from sharp edges and high-heat points.
• If chasing pinging, confirm correct octane for the engine, air leaks, clean MAF/throttle body, and up-to-date ECU fault checks before blaming the sensor.

If your 1998 Pajero is the 2.8 diesel, there’s no knock sensor to worry about — any rattly combustion noises are a different diagnostic path (injector spray pattern, pump timing, boost, EGR), not a failed KS.

Technical sources referenced: Mitsubishi Pajero/Montero Factory Service Manual 1997–1999 (6G7 Engine Electrical – Knock Sensor), Mitsubishi ASA parts catalogue (6G72/6G74 knock sensor listings, no KS for 4M40), 4M40 Engine Service Manual (no KS circuit).

Popular questions

Where is the knock sensor on a 1998 Pajero V6?
It’s bolted to the engine block in the valley of the V6, under the upper intake manifold. Access usually means removing the plenum. Look for a small round sensor with a single centre bolt and a short lead to a sub-loom.

What are the signs of a bad knock sensor on a 1998 Pajero?
Common clues are a check engine light (often P0325/P0330), dull performance, heavier fuel use, and sometimes audible pinging under load. The ECU usually retards timing to protect the engine, so it feels down on power until the fault’s fixed.

Does the 2.8 turbo-diesel 1998 Pajero have a knock sensor?
No. The 4M40 diesel doesn’t use a knock sensor because it’s a compression-ignition engine. Engine management relies on fuel injection timing, boost, air/temp sensors and other inputs rather than detecting spark knock.