UK Buyer Reliability Guide4 Known Faults Documented

Datsun 240Z / 260Z Common Problems & Reliability

The Datsun 240Z and its successor, the 260Z, are iconic Japanese sports cars that challenged European supremacy in the 1970s by offering stunning E-Type-esque styling and reliable inline-six performance. In the UK, they are highly revered classic cars, prized for their beautiful proportions, mechanical simplicity, and tunability. Due to the UK’s damp climate, surviving original examples are exceedingly rare, with rust being the ultimate enemy of these cars. Reliability of the L-series engine is legendary, provided the twin SU-style carburetors are correctly tuned. It is a fantastic choice for classic car enthusiasts who want a stunning, reliable weekend cruiser or a base for a historic track car.

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Generation Periods
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Known Issues
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Critical Faults
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Moderate Issues

Select a Model Year Period

Detailed fault breakdown, symptoms, and estimated repair bills by production year.

Most Common Datsun 240Z / 260Z Faults & Repair Costs

High Risk

Structural Corrosion (Rust)

Est. Cost£5,000–£20,000+

The S30 chassis has many hidden box sections where moisture traps and eats the metal from the inside out. Frame rails, battery trays, and floor pans are the most common failure points.

Warning Signs:

Bubbling paint, Soft spots in floor/sills, Doors not aligning (suggesting chassis flex), MOT failure for structural rot

High Risk

Overheating & Head Gasket Failure

Est. Cost£1,000–£3,000

Older L24/L26 engines can suffer from silt buildup in the radiator or blocked coolant passages in the block, leading to localized overheating and warped heads.

Warning Signs:

Temp gauge climbing in traffic, White smoke from exhaust, Mayo-like sludge under oil cap

Moderate Risk

Carburetor & Fuel System Issues

Est. Cost£200–£600

The Hitachi-SU carburettors require regular maintenance and adjustment. Worn needles, vacuum leaks and gummed-up passages cause flat spots, poor idle and hesitation. Parts are hard to source, with many owners converting to Webers.

Warning Signs:

Hesitation on acceleration, Stalling at idle, Rich or lean running, Strong fuel smell

Moderate Risk

Wiring Loom Degradation

Est. Cost£100–£500

After 45+ years, the original wiring loom becomes brittle. Corroded fuse connections, cracked insulation and perished earth straps cause intermittent electrical faults throughout the car.

Warning Signs:

Intermittent lighting failures, Gauge erratic behaviour, Flickering dashboard lights, Blown fuses

Essential Pre-Purchase Step

Buying a used Datsun 240Z / 260Z? Always check for hidden finance and write-off history.

Mechanical problems are only half the battle. Over 1 in 3 UK used cars checked have unpaid finance or accident write-off records that could cause you to lose the car or thousands in value.

Inspection Checklist for Datsun 240Z / 260Z Buyers

Rust is the absolute priority; meticulously inspect the floor pans, battery tray, spare wheel well, and chassis rails.
Check the condition of the twin Hitachi (SU-style) carburetors; they require specialist balancing for the engine to run smoothly.
Verify the health of the manual gearbox, listening for worn synchros, particularly when shifting into second gear.
Examine the interior dashboard for cracks, as original uncracked dashes are incredibly rare and expensive to replace.
Look for evidence of poor previous restorations; lots of body filler (Bondo) is a common cover-up for severe rot.
Check the electrical system, as old wiring looms can become brittle and cause erratic issues with lights and gauges.