Parts for your 2008 Holden Commodore-Knock sensor

2008 Holden Commodore knock sensor — what it does and when to sort it

Yes, a knock sensor is fitted to the 2008 Holden Commodore. Technical references including the Holden VE Series Service Manual (Engine Controls for 3.6L HFV6 LY7/LLT and 6.0L Gen IV V8 L98/L76) specify dual knock sensors for these engines. This is echoed by ACDelco’s parts catalogue for VE Commodore (MY2006–2013) and major OE supplier listings (e.g., Bosch Australia) that carry knock sensors for both V6 and V8 variants.

On the VE Commodore, the knock sensor’s job is to “listen” for detonation (knock) through the engine block and feed that info to the ECU. If knock shows up—usually from low-octane fuel, heavy load or carbon build-up—the ECU trims ignition timing and fuelling to protect the engine. That helps keep power smooth, economy decent, and the motor safe under our hot Aussie and Kiwi conditions.

For servicing, there’s no set replacement interval—knock sensors are typically “fit and forget”. They’re replaced when faulty or when there’s evidence of wiring or connector damage. Watch for a check engine light with codes like P0325–P0334, a noticeable drop in performance, poor fuel economy, pinging under load, or odd timing behaviour. Always rule out basics first: stale fuel, vacuum leaks, or carbon deposits.

Placement differs by engine. On most VE V6s, the sensors sit in the valley area beneath the intake, so replacement usually involves removing the upper intake manifold—budget some time and have fresh intake gaskets on hand. On VE V8s (Gen IV), the sensors are typically block-mounted on the sides, making access easier from underneath. Either way, fit quality OE-equivalent parts, keep connectors clean and dry, route the harness as per factory clips, and torque to the workshop manual spec to ensure proper sensitivity and sealing.

• Handy tips:
  • Use fresh 95–98 RON if the car’s tuned for it—less chance of knock, happier sensor data.
  • If the intake’s off (V6), it’s a good time to inspect PCV hoses and clean the throttle body.
  • Clear codes and perform a proper road test with a scan tool to confirm knock learn values are stable.

Popular questions

Where is the knock sensor on a 2008 VE Commodore?
V6 models generally run two sensors in the engine valley beneath the intake manifold. V8 models typically have two block-mounted sensors on the sides of the engine, accessible from underneath near the starter/engine mounts. Always confirm by VIN and engine code.

What are the symptoms of a bad knock sensor?
Common signs include a check engine light (codes P0325–P0334), reduced power, rough running or hesitation under load, worse fuel economy, and occasional pinging. The ECU may pull timing to protect the engine, which can make the car feel a bit flat.

Do knock sensors need routine replacement?
No set interval. Replace only if faulty, damaged, water-intruded, or flagged by diagnostics. When replacing, use OE-quality parts, new gaskets if the intake is removed, and torque to factory spec.