Question 1

Carburettor Deterioration and Synchronisation Drift

Accepted Answer

Rough idle, uneven power delivery, flat spots during acceleration, poor fuel economy, and difficulty starting. The engine may run rich on some cylinders and lean on others. The three twin-choke Mikuni-Solex 40PHH carburettors use rubber diaphragms, accelerator pump membranes, and needle valves that deteriorate with age and fuel exposure. Modern ethanol-blended fuels accelerate deterioration of original rubber components. The carburettors also drift out of synchronisation over time, particularly if the car is driven infrequently. Full rebuild of all three carburettors using NOS or reproduction rebuild kits. Synchronise using a vacuum gauge or Uni-Syn tool after rebuild. Specialist carburettor shops with experience on Mikuni-Solex units are rare, most 2000GT owners ship carburettors to dedicated specialists. Cost: $3,000-8,000 AUD for a full rebuild of all three units, depending on condition and parts availability.

Question 2

Timing Chain Stretch

Accepted Answer

Rattling or slapping noise from the front of the engine, particularly on cold startup. In advanced cases, the cam timing shifts, reducing power and causing rough running. The duplex timing chain that drives the twin overhead camshafts stretches over time, even on low-mileage engines, because the chain has been under tension for decades. The chain tensioner may also lose effectiveness as its spring weakens or its piston seal leaks. Replace the timing chain, tensioner, and chain guides. This requires front cover removal and careful cam timing setup. On a 2000GT, this is a specialist job, the DOHC head requires precise cam timing to avoid valve-to-piston contact. Cost: $3,000-6,000 AUD at a specialist workshop.

Question 3

Oil System Leaks (Dry Sump)

Accepted Answer

Oil puddles under the car, oil residue on the engine and chassis, dropping oil level in the external oil tank. Potential oil starvation if leaks are severe. The 3M's dry-sump system uses external oil lines, an external oil tank, and a separate scavenge pump, all with joints, seals, and fittings that deteriorate with age. Cars that sit for extended periods are particularly prone to oil line seal hardening and cracking. Inspect all oil lines, fittings, and the oil tank for weeping or active leaks. Replace any hardened or cracked lines with correct-specification replacements. The oil tank itself can develop pinhole leaks from internal corrosion if old oil with moisture contamination has been left in it. Cost: $1,000-5,000 AUD depending on the extent of replacement needed.

Question 4

Valve Clearance Drift

Accepted Answer

Ticking noise from the valve train at operating temperature, gradual loss of power, uneven cylinder performance. The shim-over-bucket valve adjustment system requires periodic re-shimming as valve seats and cam lobes wear. This is standard maintenance, but many 2000GTs have been sitting in collections for years or decades without being run, and the valve clearances were last set during a restoration that may have been ten or twenty years ago. Measure and adjust valve clearances using the correct shim sizes. This requires removing the cam covers and measuring each tappet clearance with feeler gauges, then sourcing the correct replacement shims. Shims are available from specialist suppliers. Cost: $1,000-2,500 AUD at a specialist workshop (labour-intensive).

Question 5

Radiator Core Degradation

Accepted Answer

Overheating, coolant loss, visible corrosion on radiator fins, reduced cooling efficiency. The original aluminium crossflow radiator corrodes internally from age and coolant contamination. Dissimilar metals in the cooling system (aluminium radiator, iron block, brass fittings) create galvanic corrosion if the coolant is not maintained with the correct inhibitor package. Re-core the original radiator with a new aluminium core (preserving the original tanks if possible for authenticity) or source a reproduction radiator from a specialist supplier. Always flush the entire cooling system and use fresh coolant with the correct aluminium-compatible corrosion inhibitors. Cost: $1,500-4,000 AUD for re-core or reproduction.

Question 6

Water Pump Seal Failure

Accepted Answer

Coolant dripping from the water pump weep hole, low coolant level, overheating. The water pump mechanical seal wears with age and use. On cars that sit for long periods, the seal dries out and loses its sealing surface. Rebuild or replace the water pump. NOS pumps are virtually unobtainable; rebuilding with new seals and bearings is the standard approach. Cost: $800-2,000 AUD.

Question 7

Galvanic Corrosion at Mixed-Metal Joints

Accepted Answer

White powdery corrosion on aluminium panels, particularly where they attach to the steel chassis or steel substructure. Panels may become loose or develop cracks at attachment points. Aluminium and steel in contact create a galvanic cell in the presence of moisture. Over 55+ years, even with insulating barriers between the metals, moisture finds its way in and corrosion develops. Australian coastal environments accelerate this significantly. Disassemble the affected area, remove all corrosion, treat with appropriate corrosion inhibitor, and reassemble with proper insulating barriers between dissimilar metals. On a concours-level car, this may involve panel removal, media blasting, and refinishing. Cost: $2,000-10,000+ AUD depending on severity and the panels involved.

Question 8

Steel Chassis Corrosion

Accepted Answer

Surface rust progressing to pitting and eventually perforation of the steel backbone chassis, floor sections, and structural members. The steel chassis was protected with factory-applied coatings that degrade over decades. Trapped moisture in enclosed sections accelerates hidden corrosion. Surface rust: wire brush, treat with rust converter, prime, and protect with a quality chassis sealant. Perforation: cut out affected metal and weld in new steel. Major chassis repairs require a rotisserie and specialist fabrication skills. Cost: $5,000-30,000+ AUD depending on severity.

Question 9

Fibreglass Nose Section Cracking

Accepted Answer

Hairline cracks in the fibreglass nose section, particularly around stress points (headlight surrounds, bonnet latch area, mounting flanges). Fibreglass becomes brittle with age and UV exposure. Vibration from driving and thermal cycling create stress cracks. Poor previous repairs using incorrect resin or fibre can also cause cracking. Professional fibreglass repair using the correct resin system and fibre layup. Cosmetic cracks can be filled, but structural cracks require backing reinforcement. A skilled fibreglass specialist can make invisible repairs. Cost: $500-3,000 AUD depending on extent.

Question 10

Wiring Harness Degradation

Accepted Answer

Intermittent electrical faults, lights flickering, gauges reading incorrectly, starter motor not engaging, charging system faults. The original wiring harness uses cloth-wrapped wiring with rubber insulation that becomes brittle and cracks after 55+ years. Connections corrode, solder joints develop high resistance, and insulation failure can cause short circuits. For a car that will be driven, a complete rewire using a reproduction harness (available from specialist suppliers) is the safest option. For a concours car, the original harness can be carefully restored by replacing individual wires and refreshing connections. Cost: $3,000-8,000 AUD for a reproduction harness and installation; $5,000-15,000 for an original harness restoration.

Question 11

Instrument Failure

Accepted Answer

Inaccurate or non-functioning instruments, speedometer, tachometer, gauges, or clock. The Nippon Denso instruments use mechanical movements and electrical senders that wear and fail with age. The clock mechanism is purely mechanical and often seized. Specialist instrument restoration by a qualified instrument repair shop. The instruments must be individually tested, disassembled, repaired, and recalibrated. Cost: $500-2,000 AUD per instrument.

Question 12

Second Gear Synchro Wear

Accepted Answer

Crunching or grinding when shifting into second gear, particularly on aggressive downshifts. The synchromesh ring wears thin and can no longer match shaft speeds effectively. Second gear takes the most abuse in normal driving, every downshift from third to second loads the synchro. On a car that may have been demonstrated at shows or driven enthusiastically by multiple owners over five decades, the second gear synchro wears. Gearbox removal, disassembly, and synchro ring replacement. Finding correct synchro rings requires specialist sourcing. Cost: $3,000-7,000 AUD including removal, rebuild, and reinstallation.

Question 13

Differential Whine

Accepted Answer

A high-pitched whine from the rear axle that changes with speed. May be more pronounced at certain speeds or under load. The limited-slip differential's ring and pinion gears develop wear patterns over decades of use. Incorrect backlash adjustment during previous service or restoration can also cause noise. Diagnose whether the noise is gear wear or adjustment. If adjustment, the differential can be reshimmed. If gear wear, replacement gears must be sourced, a significant challenge. Cost: $2,000-8,000 AUD depending on whether gears need replacement.

2000GT

2000GT known problems