Question 1

Worn Valve Stem Seals

Accepted Answer

Blue smoke on startup that clears after 30 seconds to a minute. May also smoke briefly on deceleration after sustained highway driving. The rubber valve stem seals harden and crack with age, allowing oil to seep past the valve stems and into the combustion chambers overnight. Replace the valve stem seals. This can be done with the head in situ using a compressed air adapter to hold the valves up, you feed compressed air into the spark plug hole to keep the valve from dropping while you swap the seal. A valve spring compressor tool is essential. Budget $50-100 for a seal kit plus a Saturday afternoon.

Question 2

Carburettor Issues (VB-VH)

Accepted Answer

Hard starting, rough idle, flat spots on acceleration, flooding, poor fuel economy, black smoke. The Stromberg and Rochester carburettors used on VB-VH models wear internally. Needle valves stick, accelerator pump diaphragms perish, jets clog, and float levels drift. Ethanol in modern fuel attacks old rubber seals and accelerator pump cups. A carburettor rebuild kit costs $40-80 and includes all the gaskets, seals, needle valve, and accelerator pump components. Rebuild it on the kitchen table over a weekend. If you're not comfortable with carby work, there are still specialists around, check local wreckers and auto-electrical shops. Alternatively, fit an aftermarket Weber or convert to EFI.

Question 3

Oil Leaks (All Holden Six and V8)

Accepted Answer

Oil on the garage floor, oil smell, oil coating on the underside of the engine. The rear main seal on the Holden six and V8 is a rope seal that hardens with age. The rocker cover gasket, timing cover seal, and oil pan gasket also deteriorate. Every old Holden six or 308 V8 leaks oil, it's a question of how much. Replace seals and gaskets as needed. The rear main seal requires the gearbox or engine to be removed, it's a significant job ($500-1,000 at a workshop). Rocker cover gaskets and timing cover seals are straightforward DIY jobs. Many owners live with a slow rear main seal leak and just keep the oil topped up.

Question 4

Overheating in Traffic

Accepted Answer

Temperature gauge climbs into the red zone in slow traffic or on hot days. May push coolant out the overflow. The VB and VC cooling systems are marginal for the V8, particularly in Australian summer conditions. The factory radiator is often undersized, the clutch fan loses efficiency when worn, and the thermostat housing gasket can leak, reducing coolant flow. Upgrade to a 3-core brass or aluminium radiator. Fit a thermo fan conversion (Davies Craig or similar) to replace the clutch fan. Ensure the thermostat is the correct rating (82°C) and the water pump is in good condition. A coolant flush and fresh coolant goes a long way.

Question 5

Worn Valve Train

Accepted Answer

Ticking or clattering from the top of the engine. May be constant or vary with RPM. The 253 and 308 V8 use adjustable rocker arms with shaft-mounted rockers. The rocker shaft wears, the rocker arm tips wear where they contact the valve stem, and pushrod tips can wear into cups. High mileage and infrequent oil changes accelerate wear. Inspect the rocker shaft for scoring and the rocker tips for excessive wear. Replace worn components. A Yella Terra roller rocker conversion eliminates the wear issue permanently and adds a useful amount of top-end power. Budget $400-800 for roller rockers.

Question 6

Timing Chain Stretch

Accepted Answer

Rattling noise from the front of the engine on cold start. Rough idle that may smooth out as the engine warms. The RB30E uses a single-row timing chain that stretches over time. The hydraulic chain tensioner compensates to a point, but once the chain is beyond the tensioner's range, it rattles against the timing cover and can skip teeth. Replace the timing chain, tensioner, and guides. The front cover must be removed. This is a full-day job. Budget $300-500 for parts and a full day of labour. Do not ignore timing chain rattle, a skipped chain will bend valves and destroy the engine.

Question 7

Oil Consumption

Accepted Answer

Oil level drops between services. No visible external leaks. The RB30E's valve stem seals deteriorate with age, and the piston rings can wear, particularly in engines that have spent most of their life doing short trips (carbon buildup glazes the bores). Start with a compression test. If compression is even across all six cylinders (above 140 psi), the issue is likely valve stem seals, replace them. If one or more cylinders are significantly lower, the engine needs a rebuild or at minimum a re-ring. Budget $1,500-3,000 for a full rebuild.

Question 8

Head Gasket Failure

Accepted Answer

Overheating, white smoke from the exhaust (especially under boost), coolant loss with no visible external leak, milky residue on the oil filler cap, coolant in the overflow bottle that smells of exhaust, bubbles in the coolant when the engine is running. The factory RB30ET head gasket is a composite (fibre/graphite) design that is marginal at the stock 7 psi boost level and fails predictably above 10 psi. The head gasket is the single most common and most critical failure on the VL turbo. Temperature cycling, age, and boost all contribute to failure. Many VL turbos have been through multiple head gaskets. Replace with a multi-layer steel (MLS) head gasket. This requires removing the head, checking the head and block surfaces for flatness (resurface if necessary), and reassembling with correct ARP head studs (stock bolts are adequate for stock boost but studs are insurance). The head should be checked for cracks, particularly between the valve seats and the combustion chambers. Budget $800-1,500 for a proper MLS head gasket job with the head checked and surfaced. This is the single most important upgrade you can do to a VL turbo, do it proactively, even if the current gasket seems fine.

Question 9

Turbocharger Wear

Accepted Answer

Blue smoke under boost, oil in the intercooler piping, excessive shaft play (compressor wheel contacts the housing), whistling or grinding noise from the turbo. The factory Garrett T3 turbo wears from age, heat cycling, and inadequate oil supply. Running the engine hard and then shutting it off immediately (instead of letting it idle for 60 seconds to cool down) accelerates turbo bearing failure. Running low-quality oil or infrequent oil changes also shortens turbo life. Replace or rebuild the turbo. A new aftermarket T3/T4 hybrid turbo is $400-800 and is a popular upgrade over the stock T3. If rebuilding the factory unit, a rebuild kit is $100-200 but requires the turbo to be sent to a turbo specialist for balancing. Always replace the oil feed and drain lines when fitting a new turbo, blocked or restricted oil feed is the number one cause of premature turbo failure.

Question 10

Air Flow Meter (AFM) Failure

Accepted Answer

Engine stumbles, surges, cuts out, or won't rev past a certain point. May run fine at idle but die under load. Intermittent misfiring. The VL turbo uses a Bosch L-Jetronic air flow meter, a flap-type meter with an internal potentiometer that measures intake airflow. The potentiometer develops flat spots (dead zones) from wear. The flap can also stick if the intake system is contaminated with oil mist from a worn turbo. Test by tapping the AFM while the engine is idling, if the idle changes, the potentiometer has flat spots. Replacement AFMs are $150-300 secondhand. Many modified VL turbos convert to a MAP (manifold absolute pressure) sensor setup, which eliminates the AFM entirely and allows for larger turbos and higher boost. This requires an aftermarket ECU or piggyback unit.

Question 11

Boost Creep / Overboosting

Accepted Answer

Boost gauge reads higher than the set level, particularly in higher gears under sustained load. The car feels faster than it should. The factory wastegate actuator weakens with age. The wastegate flap can also develop carbon buildup on the seat, preventing it from sealing properly. On modified cars, a boost leak (split intercooler hose, loose clamp) can paradoxically cause the turbo to spool harder to compensate, leading to high peak boost spikes. Replace the wastegate actuator ($100-200). Clean the wastegate flap and seat. For modified cars, fit a manual boost controller or electronic boost controller for precise boost control. Check all intercooler piping for leaks using a boost leak tester (pressurised from the intake side, listen for hissing).

Question 12

TH700-R4 Automatic Failure

Accepted Answer

Harsh 3-4 shift, slipping under load, shudder on light throttle, delayed engagement from Park to Drive. The TH700 (also known as the 4L60) is a good transmission at stock power levels but becomes marginal when power increases, even modestly. The 3-4 clutch pack is the weak point. Contaminated or burnt fluid accelerates wear. Many VL turbo autos have been abused at the traffic lights and on the drag strip. Start with a fluid and filter service. If the fluid is dark or smells burnt, the damage may already be done. A shift kit ($200-400 fitted) firms up shifts and reduces clutch slippage, extending transmission life. A full rebuild costs $1,500-2,500. For modified VL turbos making more than 200 kW at the wheels, consider a TH400 conversion, the TH400 is a 3-speed auto that's virtually indestructible.

Question 13

Clutch Slave Cylinder Failure (Manual)

Accepted Answer

Soft or spongy clutch pedal. Clutch pedal goes to the floor with no resistance. Clutch won't disengage fully, causing grinding on gear changes. The clutch slave cylinder's internal seals deteriorate with age. Brake fluid absorbs moisture over time, which corrodes the bore. Replace the clutch slave cylinder. Bleed the clutch hydraulic system. Replace the clutch master cylinder at the same time, if one has failed, the other is not far behind. Budget $100-200 for both cylinders plus fluid.

Question 14

Front Suspension Wear (All Models)

Accepted Answer

Clunking over bumps, vague steering, wandering on the highway, uneven tyre wear. The Opel-derived front suspension uses ball joints, tie rod ends, and control arm bushings that wear out. These components were designed for German roads, not Australian conditions. Corrugated dirt roads, potholes, and speed bumps accelerate wear significantly. Replace ball joints, tie rod ends, control arm bushings, and sway bar links. Do it all at once, the labour overlaps, and replacing one component at a time is a waste of money. Budget $500-1,000 for parts. Pedders, Nolathane, and SuperPro all make quality replacement components. Polyurethane bushings (Nolathane, SuperPro) last longer than rubber but transmit more NVH.

Question 15

Power Steering Rack Leak

Accepted Answer

Power steering fluid on the ground, heavy steering at low speeds, whining noise from the power steering pump. The steering rack seals wear with age. The rack boots fill with power steering fluid, check by squeezing the boots. If they're firm and oily, the rack is leaking. Replace or rebuild the steering rack. A reconditioned rack is $300-600 exchange. A new aftermarket rack is $400-800. Replacement takes 2-4 hours.

Question 16

Rear Axle Bearing Noise

Accepted Answer

Humming or whining noise from the rear that changes with speed but not with steering input. May also develop a clunk on deceleration. The rear axle bearings (wheel bearings inside the axle housing) wear with age and mileage. These are sealed units that run in the diff housing. Replace the axle bearings. This requires pulling the axle shafts. Budget $200-400 per side. Replace both sides, if one has failed, the other is not far behind.

Question 17

VL Ignition Control Module (ICM) Failure

Accepted Answer

Engine cuts out while driving. Won't restart. May restart after cooling down. Similar symptoms to the Ford TFI module failure. The VL's Hitachi ignition control module is mounted on the distributor (NA models) or coil assembly (turbo) and is subject to heat stress. Thermal cycling causes internal solder joint failure. Replace the ICM. Parts are $80-200. For the turbo model, the ICM is more accessible. Carry a spare.

Question 18

Corroded Earth Points (VL)

Accepted Answer

Intermittent electrical faults, instruments drop out, lights dim, ECU throws random codes, fuel injection behaves erratically. The VL has several critical earth points on the body and engine that corrode over time. The earth strap from the engine to the body is the most critical, if it develops high resistance, the ECU uses the sensor grounds as a return path, causing havoc with fuel injection and ignition timing. Remove, clean (wire brush to bare metal), and reassemble every earth point on the car. Apply dielectric grease to prevent future corrosion. Pay particular attention to the engine-to-body earth strap, the battery negative cable, and the earth points on the inner guard near the ECU.

Question 19

Dashboard Gauge Failures

Accepted Answer

Gauges read incorrectly, needles stick, illumination fails. The instrument cluster uses small stepper motors (VL) or thermal-type gauges (VB-VK) that fail with age. Soldered connections on the cluster circuit board develop dry joints. Remove the cluster and resolder dry joints. Replace failed illumination bulbs. For stuck gauges, replacement clusters from a wrecker are the easiest fix. Ensure you get a cluster from the same model year, wiring plugs differ between VB-VK and VL.

Question 20

Structural Rust, Sills and Rockers

Accepted Answer

Bubbling paint along the sill line, visible rust perforations underneath, soft metal when prodded. Water and road spray enter the sill cavity through drain holes, stone chips, and deteriorated seam sealer. The enclosed box section traps moisture. Once rust starts inside the sill, it spreads quickly. Minor surface rust: treat with rust converter, seal, and paint. Perforated sills: cut out the rust and weld in new metal (repair panels are available for some models) or replace the full sill section. A proper sill repair costs $2,000-5,000 per side. Bog over rust is not a repair, it's hiding the problem.

Question 21

Wheel Arch Rust

Accepted Answer

Rust visible on the inner and outer wheel arches, particularly the rear. Road spray throws water and mud into the wheel arches, where it sits against the metal. The inner wheel arch seam collects moisture and rusts from the inside out. Treat early surface rust with rust converter and stone chip paint. Perforated arches require cutting and welding. Reproduction outer wheel arch sections are available for some models. Budget $500-1,500 per arch for professional repair.

Commodore (VB-VL)

Commodore (VB-VL) known problems