Commodore (VN-VZ) / HSV

1988-2006 / Sedan / Estate / Australia

All Commodore (VN-VZ) / HSV problems All workshop problems

Common Air Conditioning

Climate Control Malfunction (VS-VZ with Auto Climate)

Symptoms

Air conditioning vents change position during acceleration (typically switch from face vents to defrost). Temperature control erratic. Blend door doesn't respond to temperature changes.

Cause

The climate control system uses engine vacuum to operate the vent flap actuators. A vacuum leak, cracked vacuum hose, or failing check valve allows manifold vacuum to drop during acceleration, causing the actuators to default to the defrost position. On the VS Statesman and VT-VZ with auto climate, the blend door actuator motor can also fail electrically.

Fix

Inspect all vacuum hoses from the intake manifold to the climate control module behind the dash.

Replace any cracked or disconnected hoses.

The vacuum check valve (a one-way valve in the vacuum supply line) is a common failure point, $10-20 for the part.

If the blend door actuator motor has failed, replacement is $50-100 for the part but labour-intensive as it sits behind the dash.

Cost mentioned in fix

$10-20 for the part$50-100 for the part

Know something we don't?

Owned a Holden Commodore (VN-VZ) / HSV? Share your experience with this issue. What worked, what didn't, costs, tips. Help the community.

Submit an update

// More Commodore (VN-VZ) / HSV problems

Other known issues

Common Air Conditioning

Compressor Failure (All Models)

Air conditioning blows warm air. Compressor clutch doesn't engage. Unusual noise (grinding, squealing) from the compressor when engaged.

Common Engine, V6 (Buick/Ecotec 3.8L, VN-VY)

Intake Manifold Gasket Leak

Coolant leak at the junction of the intake manifold and cylinder heads. May present as coolant loss without a visible external leak (coolant enters the intake ports), or as a coolant stain on the side of the engine. Engine may run rough or misfire if coolant enters the combustion chamber.

Critical Engine, V6 (Buick/Ecotec 3.8L, VN-VY)

Harmonic Balancer Failure (Ecotec, VS onwards)

A wobbling pulley on the front of the crankshaft. Knocking or rattling noise from the front of the engine. The drive belt may track poorly or come off.

Common Engine, V6 (Buick/Ecotec 3.8L, VN-VY)

Supercharger Bypass Valve Failure (L67 supercharged V6)

Loss of boost, rattling from the supercharger, reduced performance. The supercharger may make a whining noise that changes with the valve's operation.

Critical Engine, V6 (Alloytec 3.6L, VZ)

Timing Chain and Guide Failure

Rattling noise on cold start that may persist after warm-up. Check engine light with codes related to camshaft timing. Rough idle, misfiring, loss of power. In severe cases, the engine won't start or runs extremely poorly.

Critical Engine, V6 (Alloytec 3.6L, VZ)

Oil Leaks from Timing Cover

Oil weeping or dripping from the front of the engine, behind the harmonic balancer area.

All Commodore (VN-VZ) / HSV problems