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MOTRS

HK-HG Monaro / GTS

1968-1971 / Coupe / Australia

All HK-HG Monaro / GTS problems All workshop issues
Common Engine, Chevrolet V8 (327ci / 350ci)

Hydraulic Lifter Noise

Symptoms

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.

Cause

The Chevrolet small-block uses hydraulic lifters that compensate for valve train clearance changes as the engine heats up. Over time, the lifters wear internally, develop internal leaks, or collapse. Dirty or old oil exacerbates the problem, the lifters rely on clean oil to maintain pressure.

Fix

Start with an oil change using quality 15W-40 or 10W-40 and a can of engine flush.

If the ticking persists, individual lifters can be replaced.

Budget $10-20 per lifter, and there are 16 of them.

Replacing all 16 is recommended, if one has failed, the others are wearing.

Access requires removing the intake manifold, rocker arms, and pushrods.

Budget a full day's labour.

Cost mentioned in fix
Budget $10-20 per lifter

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Other known issues

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

Oil Leaks, Rear Main Seal

Oil drips from the bellhousing area. Oil accumulates on the underside of the engine and transmission.
Common Engine, Holden Six (186ci) and V8 (253ci)

Valve Train Wear (253 V8)

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