Parts for your 2000 Holden Commodore-Knock sensor

2000 Holden Commodore Knock Sensor

Yes, the 2000 Holden Commodore uses a knock sensor. This applies across its engines of the era, including the 3.8 litre Ecotec V6 (L36), the supercharged L67 V6, and the Gen III 5.7 litre LS1 V8. Factory literature such as the Holden VT/VX Service Manual (Engine Controls), GM Holden Service Information (Techline/SI), and AC Delco/Delphi service data specify a knock sensor and related diagnostic trouble codes (for example P0325/P0330). Bosch technical papers on knock control also describe the same style of piezoelectric sensor used on these engines.

The knock sensor’s job is simple but vital: it listens for the high-frequency vibrations caused by detonation (pinging) and lets the engine control module trim ignition timing to keep the engine safe while still making good power. On the naturally aspirated V6 there’s a single block-mounted sensor, the LS1 V8 uses two sensors mounted in the valley under the intake. Many supercharged L67 setups use two sensors as well. Location and access do vary, so checking the engine-specific procedure is wise.

It’s not a scheduled service item, but it does deserve attention when chasing pinging, flat performance, odd fuel economy, or a check-engine light. Poor grounds, tired engine mounts, or rattly accessories can cause false knock, so it pays to rule those out. If replacement is needed, use a quality sensor and tighten it to the factory torque spec, as clamping load affects how the sensor “hears.” On LS1s, water ingress under the intake can corrode the sensors and sub-loom, many techs replace both sensors and the harness together and reseal the grommets. On the V6, access is usually from underneath the car, keep the connector clean and route the loom away from exhaust heat.

Handy signs it’s time to check the knock sensor or its wiring:

• Pinging under load or uphill on regular unleaded
• Limp performance with no obvious misfire
• DTCs P0325 or P0330 stored in the ECU

A quick road test after repairs is essential. Clear the codes, run the car through a few heat cycles, and listen for any rattles under the bonnet that could confuse the sensor. Using the correct octane petrol and keeping the cooling system healthy will also help the sensor and ECU keep timing right on the money for Aussie and Kiwi conditions.

Popular questions

Where is the knock sensor on a 2000 Commodore?
On the 3.8 litre V6, it’s typically threaded into the engine block around the mid-to-rear area, accessed from underneath. The LS1 V8 has two sensors under the intake manifold on the valley cover. Supercharged L67 models commonly use two block-mounted sensors. Always confirm by engine code and consult the factory procedure for exact placement.

What are the symptoms of a failing knock sensor?
Common signs include pinging under load, lazy throttle response, poorer fuel economy, and a check-engine light with DTC P0325 or P0330. Sometimes the ECU will over-retard timing to protect the engine, which feels like a power drop without a misfire.

Should the knock sensor be replaced as routine maintenance?
No. It’s a fit-and-forget part unless it faults or the harness is damaged. That said, on LS1 cars it’s smart to inspect or pre-emptively replace the sensors and sub-loom if the intake is off, especially if there’s evidence of moisture in the valley.