Datsun 1600/510, Known Issues and Common Problems
Overview
The Datsun 510/1600 is a mechanically simple car with fundamentally sound engineering. The L-series engine is robust, the independent rear suspension was ahead of its class, and the driveline is tough. The car’s mortal enemy is corrosion — the 510/1600 rusts with a ferocity that is remarkable even by late 1960s standards. Beyond rust, the issues are typical of a 55-year-old car with thin steel, basic electrics, and decades of accumulated wear.
Body and Structure
Floor Pan Corrosion
What happens: Soft, spongy, or perforated floor pans. Wet carpet after rain. Road noise increases noticeably as the floors thin. In extreme cases, the floor is partially or entirely gone.
Why it happens: The floor pans are thin-gauge steel with minimal factory corrosion protection. Road spray from below and water entry from above (through deteriorated seals) attack the metal from both sides. Australian humidity accelerates the process even without road salt.
How to fix it: Weld in repair panels. Some reproduction floor sections are available; others must be fabricated from flat sheet steel by a competent panel beater. This is a common and well-understood repair in the 510 community. Cost: $500—1,500 per section, depending on extent and fabrication requirements.
Severity: Critical. Structural floors contribute to body rigidity and occupant safety.
Sill (Rocker Panel) Corrosion
What happens: The outer sill skin softens and crumbles. Door alignment changes as the inner sill structure weakens. The car may creak or flex over bumps.
Why it happens: Box-section sills trap water when drain holes block. Corrosion works from inside, so the damage is often worse than it appears from outside.
How to fix it: Full sill replacement — inner and outer sections. Some repair panels are available; others require fabrication. Cost: $1,000—2,500 per side.
Severity: Critical. The sills are primary structural members on the monocoque body.
Inner Guard and Strut Tower Corrosion
What happens: The inner front fenders around the MacPherson strut top mounts corrode and thin. In severe cases, the strut tower can deform under load.
Why it happens: Road spray and trapped moisture in the double-skinned areas around the radiator support and inner guards. Poor drainage design traps water.
How to fix it: Fabricate and weld repair sections. Strut tower reinforcement plates are available from some specialists. Cost: $800—2,000 per side.
Severity: Critical. Compromised strut towers affect front suspension geometry and are a safety hazard.
Rear Wheel Arch Corrosion
What happens: Bubbling paint, perforation, and structural weakening of the inner and outer rear wheel arches.
Why it happens: Road spray and debris accumulate between the inner and outer skins. The rear suspension mounting points are nearby, so severe rust can affect them.
How to fix it: Cut out and replace with new metal. Some reproduction arch sections are available. Cost: $500—1,500 per side.
Severity: Urgent if approaching suspension mounts. Cosmetic if limited to the outer skin.
Spare Tyre Well Corrosion
What happens: The boot floor around the spare tyre well perforates. Water pools in the spare tyre recess.
Why it happens: Water enters through tail-light seals and boot seal failures. The spare tyre well is the lowest point and collects water that doesn’t drain.
How to fix it: Weld in repair sections. Cost: $300—800.
Severity: Needs attention. Not immediately structural but indicates water entry that will spread.
Engine — L-Series (L16)
Oil Leaks
What happens: Oil seepage and dripping from multiple points on the engine. Common leak points: valve cover gasket, timing cover gasket, oil pan gasket, rear main seal, distributor shaft seal, cam seal.
Why it happens: The L-series uses cork, rubber, and paper gaskets that deteriorate over 55 years. The L16 was not the tightest engine when new; age makes everything worse.
How to fix it: Systematic reseal. Replace all gaskets and seals in one session. The rear main seal requires gearbox removal. Cost: $150—300 DIY for gasket set, $500—1,000 at a workshop for a full reseal.
Severity: Needs attention. Oil on the exhaust manifold is a fire risk. Persistent leaks lead to low oil level if not monitored.
Timing Chain and Tensioner Wear
What happens: Rattling or slapping noise from the front of the engine, particularly on cold start. In severe cases, the chain skips a tooth, altering valve timing and potentially causing valve-to-piston contact.
Why it happens: The timing chain stretches and the tensioner wears over 100,000+ km. The chain guide rails also wear and can break, allowing the chain to contact the timing cover.
How to fix it: Replace the timing chain, tensioner, and guides as a set. This is a common and well-documented job on the L-series. Cost: $200—500.
Severity: Urgent once the rattle is audible. A skipped chain on the L16 can cause valve damage.
Overheating
What happens: Temperature gauge climbs, particularly in traffic or on hot days. Coolant loss.
Why it happens: The L16’s cooling system is adequate in temperate climates but marginal in Australian summer heat. The original radiator loses efficiency with age. Thermostat sticking, water pump wear, and collapsed hoses all contribute.
How to fix it: Aluminium radiator upgrade ($250—450), new thermostat ($15—30), new water pump ($50—100), and all new coolant hoses. Total cooling system refresh: $300—600.
Severity: Critical. Overheating causes head gasket failure and head warping on the aluminium-head L-series.
Head Gasket Failure
What happens: Coolant in the oil (milky residue on dipstick), oil in the coolant, white exhaust smoke, persistent overheating, coolant consumption.
Why it happens: The L-series has a cast-iron block and aluminium head — different thermal expansion rates stress the head gasket, particularly after overheating episodes. The original asbestos head gaskets deteriorate with age.
How to fix it: Remove the head, check it for warping and cracks (skim if necessary), replace with a modern composite head gasket. Cost: $500—1,200 for head gasket replacement including head skim.
Severity: Urgent. Continuing to drive with a blown head gasket causes progressive engine damage.
Carburettor Wear
What happens: Rough idle, hesitation on acceleration, poor fuel economy, rich or lean running.
Why it happens: The Hitachi SU-type carburettor develops throttle shaft bushing wear, needle and jet wear, and perished diaphragms. Float valves stick. Jets block with varnish from old fuel.
How to fix it: Rebuild with a carburettor kit ($40—80). If the throttle shaft bushings are worn, the carburettor body needs rebushing (specialist job: $60—120). Many 510 owners upgrade to twin round-top SU carburettors or a Weber DCOE setup for better performance. Cost: $300—800 for a Weber DCOE conversion.
Severity: Needs attention. A poorly running carburettor affects driveability and economy.
Gearbox
Synchro Wear
What happens: Grinding when shifting into 2nd or 3rd gear, particularly on quick downshifts.
Why it happens: The standard 4-speed gearbox is not a strong unit. The synchro rings wear, particularly with enthusiastic driving. The gear teeth are adequate but not over-engineered.
How to fix it: Rebuild with new synchro rings ($600—1,200) or swap to a 5-speed from a later Datsun (240Z, 280ZX, or similar). The 5-speed is a stronger unit with an overdrive ratio that makes highway cruising more relaxed. 5-speed conversion: $500—1,500 including gearbox, crossmember modification, and propshaft adjustment.
Severity: Needs attention. Double-clutching extends synchro life.
Brakes
Inadequate Drum Brakes
What happens: Long stopping distances, brake fade under repeated heavy braking, pulling to one side, poor pedal feel.
Why it happens: The standard 510/1600 has drum brakes on all four wheels. This was adequate by 1967 standards but is dangerously inadequate by modern standards, particularly if the car has been fitted with a more powerful engine.
How to fix it: Convert the front brakes to discs. Conversion kits using later Datsun components (280ZX callipers and rotors) are available from specialists. This is one of the most important safety upgrades for any 510/1600 that will be driven in modern traffic. Cost: $500—1,000 for a front disc conversion.
Severity: Critical for safety. Do not drive a 510/1600 with all-drum brakes in modern traffic conditions without extreme caution.
Brake Component Deterioration
What happens: Spongy pedal, pulling to one side, brake fluid leaks.
Why it happens: The wheel cylinders, master cylinder, and brake hoses deteriorate over 55 years. Rubber seals swell and leak. Flexible hoses develop internal restrictions that prevent proper fluid flow.
How to fix it: Replace the master cylinder ($60—120), all wheel cylinders ($30—60 each), and all flexible brake hoses ($40—80 per set). Rebuild kits are available for most components. Total brake system refresh: $200—500 (drum system) or $500—1,000 (including disc conversion).
Severity: Critical. Brakes are life-safety components.
Electrical
Basic Wiring Deterioration
What happens: Intermittent lights, non-functioning accessories, no-start conditions.
Why it happens: The 510/1600’s electrical system is basic but functional when new. After 55 years, the wiring insulation becomes brittle, connectors corrode, and earth connections develop resistance. Previous owners’ modifications (stereos, additional lights, engine swaps) often add poorly executed wiring.
How to fix it: Inspect the wiring harness, repair damaged sections, clean all connectors and earth points. A full replacement wiring harness: $400—800. Cost for targeted repairs: $100—300.
Severity: Needs attention. Electrical fires from deteriorated wiring are a real risk.
Alternator/Generator Failure
What happens: Dim lights, dead battery, charging warning light.
Why it happens: Early 510/1600s use a generator (dynamo); later cars have an alternator. Both types have worn brushes and failed regulators after 55 years.
How to fix it: Replace or rebuild. An alternator upgrade (if still on a generator) improves charging significantly. Cost: $80—200.
Severity: Needs attention. A dead charging system strands you.
Suspension
Bushing Deterioration
What happens: Clunking from the suspension, vague steering, uneven tyre wear, poor handling.
Why it happens: All the rubber bushings in the front struts, rear semi-trailing arms, and anti-roll bar (if fitted) have perished over 55 years. Worn bushings allow the suspension geometry to shift under load, degrading the 510’s normally excellent handling.
How to fix it: Replace all bushings. Polyurethane bushings are available for most locations and are more durable than rubber. Front suspension rebuild kit: $150—300. Rear trailing arm bushings: $80—150 per side.
Severity: Needs attention. Worn bushings waste the 510’s chassis potential.
Shock Absorber Wear
What happens: Wallowing, bouncing, poor body control, excessive body roll.
Why it happens: The original shock absorbers are long past their service life. Even replacement shocks fitted 20 years ago are likely worn.
How to fix it: Replace with quality aftermarket dampers. KYB and Koni units are available. Cost: $200—400 per set.
Severity: Needs attention. Worn dampers compromise handling and safety.
Preventive Maintenance
- Inspect for rust every 12 months. Floors, sills, inner guards, strut towers, rear arches. This is the most important thing you can do for a 510/1600.
- Convert to front disc brakes if still on all drums. Non-negotiable for safe modern driving.
- Maintain the cooling system. Aluminium radiator, fresh hoses, correct thermostat.
- Change engine oil every 5,000 km with 20W-50 mineral oil.
- Replace the timing chain and tensioner if their history is unknown.
- Refresh all suspension bushings. This restores the 510’s superb handling.
- Check and clean all electrical earth connections annually.
- Join the Datsun community. The 510/1600 community is active, knowledgeable, and generous with advice and parts leads. Forums and clubs are invaluable for keeping these cars alive.
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