240Z / 260Z / 280Z

1969-1978 / Coupe / Japan

All 240Z / 260Z / 280Z problems All workshop issues

Common Engine

Valve Stem Seal Deterioration

Symptoms

Blue-grey smoke on startup (after the car has been sitting). Blue smoke on deceleration (lifting off the throttle after sustained acceleration). Oil consumption increases, typically 1L per 2,000-3,000 km.

Cause

The original valve stem seals are rubber and harden with age, losing their ability to prevent oil from seeping past the valve stems into the combustion chambers.

Fix

Replace the valve stem seals.

This can be done with the head in place using a valve spring compressor and compressed air to hold the valves up (feed air into the spark plug hole with a fitting).

Cost: $50-100 for a seal set.

The job takes 3-4 hours.

If the car is consuming significantly more than 1L per 3,000 km, the valve guides may also be worn and require replacement (head must come off for this).

Cost mentioned in fix

Cost: $50-100 for a

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// More 240Z / 260Z / 280Z problems

Other known issues

Common Engine

SU Carburettor Wear and Tuning Issues (240Z, 260Z)

Poor idle, hesitation on acceleration, rich or lean running, black smoke, poor fuel economy, difficult starting. The engine may run well at some RPMs but poorly at others.

Common Engine

Fuel Injection Faults (280Z)

Hard starting (especially cold), rough idle, hesitation, rich or lean running, stalling. The engine management warning light may illuminate.

Critical Engine

Timing Chain Stretch

Rattling or slapping noise from the front of the engine, particularly on cold start. The noise may diminish as the engine warms but does not fully disappear.

Critical Engine

Head Gasket Failure

Coolant loss with no visible external leak. White smoke from the exhaust. Milky residue on the oil filler cap. Overheating. Coolant in the oil or oil in the coolant.

Minor Rust

Structural Rust, Floors, Sills, Strut Towers

Perforations in the floor pans, sill (rocker panel) box sections, and front strut tower mounting points. In advanced cases, the floorboard flexes underfoot, the sills crumble when prodded, and the strut towers crack under suspension load.

Common Rust

Battery Tray Corrosion

The battery tray (right-hand side of engine bay on RHD cars) corrodes and eventually perforates. Rust spreads into the inner guard and firewall.

View all 17 240Z / 260Z / 280Z problems