Parts for your 2018 Holden Colorado-Knock sensor

2018 Holden Colorado knock sensor — is it actually a thing?

Short answer: for the 2018 Holden Colorado sold in Australia and New Zealand (the 2.8L Duramax turbo‑diesel, RPO LWN), there isn’t a knock sensor fitted. GM technical sources — including the Holden/GM Global Service Information for RG Colorado (Engine Controls – 2.8L Duramax LWN) and the GM/ACDelco electronic parts catalogue — list no knock sensor for the LWN diesel. Knock sensors do appear in documentation for petrol engines used in other markets, but they’re not part of the Aussie/NZ 2018 Colorado ute.

Why’s that the case? Knock sensors are primarily a petrol‑engine device. They listen for abnormal combustion (pinging/knock) and let the ECU pull back spark timing to protect the engine. The Colorado’s 2.8L is a compression‑ignition diesel, so there’s no spark timing to adjust. What sounds like “diesel knock” under the bonnet is largely normal combustion noise that a conventional knock sensor can’t meaningfully interpret the way it would on a petrol. Instead, the Colorado’s ECU manages combustion using injection strategy (pilot/main/post injections), fuel rail pressure, boost/EGR control and data from sensors like MAP, MAF, crank and cam angle, coolant and intake air temps.

• Compression‑ignition engines don’t use spark, so knock control via timing retard isn’t needed.
• Diesel combustion is inherently noisier, a typical petrol‑type knock sensor would flag false events.
• The ECU shapes combustion via injector timing/quantity and rail pressure, not spark timing.
• GM’s diesel engine control strategy and parts listings for LWN show no knock sensor input or part.

What this means for servicing: there’s no knock sensor to maintain or replace on a 2018 Colorado diesel. If a generic scan tool throws a P0324/P0325 “knock sensor” code on this ute, it’s usually a database mis‑map or the tool is set to a petrol engine profile. Focus diagnosis on what actually affects diesel combustion quality:

• Fuel quality and cetane rating, drain water separators and replace filters on schedule.
• Injector balance rates, leakage and pilot injection performance.
• Air system integrity (intake leaks, MAP/MAF accuracy), EGR/VGT operation and software updates.
• Engine/gearbox mounts and accessories that can mimic knock with vibration or rattle.

If someone’s importing or working on a petrol‑powered Colorado/Colorado‑equivalent from another market, that’s a different story — those engines do use knock sensors. But for a 2018 AU/NZ Colorado 2.8 diesel, a knock sensor simply isn’t part of the package.

Popular questions

Does a 2018 Holden Colorado have a knock sensor?
On the 2.8L Duramax diesel sold in Australia and New Zealand, no. GM Service Information and the GM/ACDelco parts catalogue don’t list a knock sensor for the LWN engine. Petrol variants in other markets can have them, but they weren’t offered here in 2018.

I’ve got a P0325 “knock sensor” code on my diesel Colorado — what now?
That code label is for petrol engines. On the LWN diesel it’s typically a generic scan tool interpretation issue. Re‑scan with software that’s set to the correct engine, then chase real diesel‑related faults: injector balance, fuel pressure, air leaks, EGR/boost control or wiring grounds.

What causes knock‑like noise on a Colorado diesel, and is it harmful?
Cold‑start clatter, low‑cetane fuel, worn injectors or incorrect pilot injection can make the engine sound “knocky”. Some clatter is normal, but excessive rattle under load warrants a check of fuel quality, injector performance and ECU calibration. Get it looked at before it snowballs into hard‑starting or smoke issues.