HK-HG Monaro / GTS

1968-1971 / Coupe / Australia

All HK-HG Monaro / GTS problems All workshop issues

Common Engine, Holden Six (186ci) and V8 (253ci)

Oil Leaks, Rear Main Seal

Symptoms

Oil drips from the bellhousing area. Oil accumulates on the underside of the engine and transmission.

Cause

The Holden six and 253 V8 use a rope-style rear main seal that hardens with age. Every old Holden engine leaks from the rear main seal to some degree.

Fix

Replace the rear main seal.

Requires engine or gearbox removal.

Budget $500-1,000 at a workshop.

Many owners tolerate a slow leak and keep the oil topped up.

Cost mentioned in fix

Budget $500-1,000

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Other known issues

Common Engine, Holden Six (186ci) and V8 (253ci)

Valve Train Wear (253 V8)

Ticking or clattering from the top of the engine. Reduced power.

Critical Engine, Chevrolet V8 (327ci / 350ci)

Intake Manifold Gasket Leaks

Coolant leak at the front or rear of the intake manifold. Coolant may drip externally or, worse, leak internally into the engine oil. May also cause a vacuum leak, resulting in rough idle and poor fuel economy.

Common Engine, Chevrolet V8 (327ci / 350ci)

Rochester Quadrajet Carburettor Issues

Hesitation on acceleration (bog), flooding, fuel smell, hard starting when hot, black smoke, erratic idle.

Critical Engine, Chevrolet V8 (327ci / 350ci)

Overheating Under Load

Temperature gauge climbs on highway drives, particularly towing or climbing hills. May push coolant out the overflow. Engine pings (detonation) under load.

Common Engine, Chevrolet V8 (327ci / 350ci)

Hydraulic Lifter Noise

Ticking or clattering from the top of the engine that varies with RPM. May be audible at idle and disappear at higher RPM, or vice versa.

Common Transmission

Muncie 4-Speed Synchro Wear

Grinding on gear changes, particularly second and third gear. Difficulty selecting gears under load.

View all 18 HK-HG Monaro / GTS problems