Question 1

Worn Bearings and Low Oil Pressure

Accepted Answer

Oil pressure drops below 25 psi at idle when hot. Knocking from the bottom end under load. The main and big-end bearings wear over 50+ years. The oil pump also wears, reducing delivery pressure. Infrequent oil changes accelerate bearing wear. Bottom-end rebuild, new bearings, check and potentially regrind the crank. Budget $1,500-2,500 at a machine shop. The Holden six is one of the simplest engines in the world to rebuild, it's a straightforward, honest motor that rewards basic maintenance.

Question 2

Triple Carburettor Synchronisation (XU-1)

Accepted Answer

Rough idle, uneven running, flat spots, poor throttle response. The engine feels rough and unbalanced. The GTR XU-1's triple Stromberg carburettors must be precisely synchronised, all three must deliver the same airflow at the same throttle opening. Over time, the individual carburettors wear at different rates, the linkage develops play, and the synchronisation drifts. Modern fuel with ethanol also attacks the original rubber components in the carburettors. Rebuild all three carburettors with quality kits ($150-300 total), then synchronise using a vacuum gauge or Unisyn tool. Each carburettor's idle mixture, idle speed, and throttle linkage must be adjusted individually, then balanced against the others. This is a skilled job, if you're not experienced with multiple carburettor setups, find a specialist. Budget $300-500 for a professional rebuild and synchronisation.

Question 3

Valve Stem Seal Deterioration

Accepted Answer

Blue smoke on startup that clears within a minute. May also smoke briefly on deceleration. The rubber valve stem seals harden and crack with age. Oil seeps past the valve stems into the combustion chambers. Replace the valve stem seals. Can be done with the head in situ using compressed air to hold the valves up. Budget $50-100 for a seal kit.

Question 4

Overheating in the Compact Engine Bay

Accepted Answer

Temperature gauge climbs in traffic or under sustained load. May push coolant out the overflow. Engine pings (detonation) under acceleration. The 253 and 308 V8 engines generate significantly more heat than the six-cylinder they replaced in the Torana's engine bay. The engine bay was originally designed for the six, and while the LH/LX were adapted for the V8, the cooling system clearances are tighter than in the larger HQ/HJ/HX sedans. The factory radiator is often marginal, particularly in the 308. Hot exhaust manifolds radiate heat into the confined space, and the thermostat housing is close to the carburettor, causing fuel vaporisation (vapour lock) in extreme conditions. Upgrade the radiator to a 3-core brass or aluminium unit ($400-800). Fit an electric thermo fan behind the radiator ($150-250) to improve low-speed cooling. Wrap or ceramic-coat the exhaust manifolds to reduce underbonnet heat. Ensure the thermostat is the correct 82°C rating. Check the water pump for leaks and impeller erosion. Consider an insulating gasket between the carburettor and intake manifold to reduce vapour lock.

Question 5

Rochester Quadrajet Carburettor Problems

Accepted Answer

Hesitation off idle (the classic "Q-jet bog"), flooding, hard starting when hot, black smoke, fuel smell. The Q-jet's primary metering system is sensitive to wear. The accelerator pump fails, the power piston sticks, the float level drifts, and the needle valve leaks. Modern ethanol-blended fuel attacks old rubber components. Rebuild with a quality rebuild kit ($80-150). Pay particular attention to the float level, an incorrect float level causes 90% of Q-jet running problems. Alternatively, replace with a Holley 4-barrel or Edelbrock Performer carburettor ($400-800) for simpler tuning and better parts availability.

Question 6

Valve Train Noise (308 V8)

Accepted Answer

Ticking or clattering from the top of the engine. May vary with RPM. The 308's shaft-mounted rocker arms wear at the tips and the shaft develops scoring. The pushrod tips can also cup. This is accelerated by infrequent valve adjustments and oil that's too thin. Inspect and replace worn components. A Yella Terra roller rocker conversion ($400-800) is the definitive fix, it eliminates the wear mechanism entirely and frees up a small amount of power by reducing friction.

Question 7

Oil Leaks

Accepted Answer

Oil on the garage floor, oil smell, oil coating on the underside of the engine. The 253 and 308 share the same rope-style rear main seal as the Holden six, it always leaks eventually. The rocker cover gaskets, timing cover seal, and oil pan gasket all deteriorate with age. Replace gaskets and seals as needed. The rear main seal requires engine or gearbox removal ($500-1,000 at a workshop). Many owners tolerate a slow leak.

Question 8

Trimatic Automatic Reliability

Accepted Answer

Slipping under load, delayed engagement, harsh shifts, overheating. The Trimatic may also develop a shudder on light-throttle upshifts. The Trimatic 3-speed automatic was Holden's own design, and it's adequate at stock power levels behind the six-cylinder engine. Behind the V8, particularly the 308, it's marginal. The clutch bands wear, the internal seals harden, and the fluid breaks down faster under the V8's greater torque output. Cars that have been driven hard or modified to produce more power overwhelm the Trimatic quickly. A fluid and filter service ($100-150) can improve shift quality if the damage isn't too far advanced. A shift kit ($200-400 installed) firms up shifts and reduces clutch slippage. For a full rebuild, budget $1,200-2,000. For V8 cars making more than stock power, consider a TH350 or TH400 conversion, both are significantly stronger than the Trimatic and bolt in with adapter kits.

Question 9

Gearbox Synchro Wear (Manual)

Accepted Answer

Grinding on gear changes, particularly second and third gear. Synchro rings wear from use. Second gear wears fastest because it's the most-used ratio. Gearbox rebuild with new synchro rings. Budget $800-1,500. The M21 4-speed is well-documented with good parts availability.

Question 10

Clutch Hydraulic Failure

Accepted Answer

Clutch pedal goes to the floor, won't return, or feels spongy. Clutch won't disengage fully. The clutch master cylinder and slave cylinder seals deteriorate with age. Brake fluid absorbs moisture, causing internal corrosion. Replace both the clutch master and slave cylinders ($100-200 for both). Flush the system with fresh DOT 3 fluid.

Question 11

Front Strut Mount Failure (LH/LX)

Accepted Answer

Clunking over bumps, particularly at the front. Steering feels vague. Noise when turning the steering wheel at low speed. The LH and LX use MacPherson strut front suspension with rubber top mounts. These mounts deteriorate with age and loading, allowing the strut to move within the mount. Replace the strut top mounts ($50-100 per side). This is a straightforward job, the strut assembly must be removed and the spring compressed to access the top mount. Replace the strut bearings at the same time.

Question 12

Worn Rear Trailing Arm Bushings

Accepted Answer

Clunking from the rear under acceleration and braking. Rear axle wanders. The car feels loose and imprecise through corners. The rubber bushings in the rear trailing arms deteriorate over time. The trailing arms locate the rear axle laterally and longitudinally, when the bushings wear, the axle can move under load. Replace the trailing arm bushings. Polyurethane replacements (Nolathane, SuperPro) are recommended, they last longer than rubber and provide more precise axle location, though they transmit slightly more road noise. Budget $150-300 for a complete set.

Question 13

Rear Coil Spring Sag

Accepted Answer

The rear of the car sits lower than it should. May bottom out over bumps. Uneven stance when viewed from the side. Coil springs lose their temper over decades. Cars that have carried heavy loads or towed trailers sag faster. Replace with new springs. Pedders, King Springs, and Lovells all offer Torana-specific replacement springs in standard and lowered heights. Budget $200-400 per pair.

Question 14

Rear Quarter Rust

Accepted Answer

Rust in the rear quarter panels, behind and below the rear wheels. Bubbling paint, perforation, structural deterioration. The rear quarters on the Torana trap road spray between the inner and outer skins. The complex shapes create pockets where water sits. The dog-leg area where the rear quarter meets the sill is particularly vulnerable. Cut out rusted metal and weld in new sections. Reproduction outer quarter panels are available from specialists. The inner structure may also need fabrication. Budget $1,500-3,000 per side for a comprehensive repair by a skilled panel beater.

Question 15

Floor Pan Corrosion

Accepted Answer

Perforated floor pans, soft metal, visible rust from inside (under the carpet) or outside (from underneath). Water ingress through door seals and firewall, combined with road spray from below. The Torana's compact floor area means any rust quickly reaches structural areas. Reproduction floor pan sections are available. Cut and weld new metal. Budget $2,000-6,000 for comprehensive floor repair.

Question 16

Inner Guard and Chassis Rail Rust

Accepted Answer

Hidden rust in the front inner guards and the chassis rails where they pass through the engine bay. Road spray and mud collect in the inner guard area, sitting against the metal for months or years. The engine bay heat cycling accelerates corrosion once it starts. Clean out the inner guards, cut away rusted metal, fabricate and weld new sections. Budget $1,500-4,000 per side. This is hidden structural work that must be done properly.

Question 17

Windscreen and Rear Window Rust

Accepted Answer

Rust under the glass seals, visible as bubbling paint around the windscreen or rear window edges. Water penetrates between the rubber seal and the metal, causing rust that's invisible until the glass is removed. Remove the glass, treat all rust, prime, and reseal with new rubber seals. Budget $400-800 per window including new seals.

Question 18

Alternator and Charging Issues

Accepted Answer

Battery goes flat, dim headlights, ammeter shows discharge. The alternator's internal components (brushes, bearings, voltage regulator) wear over time. The external wiring and connections corrode. Replace or recondition the alternator ($150-300). Clean all electrical connections and earth points.

Question 19

Earth Point Corrosion

Accepted Answer

Intermittent electrical faults, instruments flicker, lights dim, engine runs erratically. The body-mounted earth points corrode over time, creating high resistance in the electrical circuits. Clean every earth point to bare metal and apply dielectric grease. Pay particular attention to the engine-to-body earth strap and the battery negative cable connection.

Torana (LJ-LX) / GTR / SLR / A9X

Torana (LJ-LX) / GTR / SLR / A9X known problems