Commodore (VN-VZ) / HSV

1988-2006 / Sedan / Estate / Australia

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

Critical Engine, V8 (Holden 304, VN-VS)

Oil Pump Drive Shaft Failure

Symptoms

Sudden loss of oil pressure. Oil pressure warning light illuminates. Engine noise increases rapidly. Catastrophic engine failure if not caught immediately.

Cause

The 304 V8's oil pump is driven by a shaft from the distributor (or a dedicated drive on EFI models). The shaft can develop a twist or break, stopping the oil pump entirely.

Fix

Replace the oil pump drive shaft.

This requires removing the distributor (where fitted) and extracting the shaft.

Parts: $30-60.

The bigger cost is the damage done before you noticed.

If oil pressure drops, stop the engine immediately, do not drive the car to a workshop.

Cost mentioned in fix

$30-60

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

Other known issues

Common Engine, V8 (Holden 304, VN-VS)

Hydraulic Lifter Noise

Ticking or tapping noise from the top of the engine, worst on cold start. May persist for several minutes or be constant.

Common Engine, V8 (Holden 304, VN-VS)

Rear Main Seal Leak

Oil drips from the junction of the engine and gearbox. Oil may be visible on the underside of the bellhousing.

Critical Engine, V8 (Holden 304, VN-VS)

Crank Angle Sensor Failure (VN-VS)

Engine stalls without warning while driving, particularly when hot. Intermittent no-start condition. Engine cranks but won't fire. May restart after cooling down for 20-30 minutes.

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.

All Commodore (VN-VZ) / HSV problems