300ZX (Z32)

1989-2000 / Coupe / Convertible / Japan

All 300ZX (Z32) problems All workshop issues

Common Engine -- VG30DE/DETT (All Models)

Spark Plug Access (Rear Bank)

Symptoms

The rear three spark plugs become fouled, worn, or fail, causing misfires, rough running, and reduced power.

Cause

The spark plugs wear normally -- but the rear bank plugs are buried under the intake plenum and are extremely difficult to access. Many owners defer the rear plug change because of the labour involved, which means the plugs run far beyond their service life.

Fix

Remove the upper intake plenum to access the rear bank.

Replace all six plugs simultaneously.

This is a 2--4 hour job depending on experience.

Cost: $200--500 at a workshop (mostly labour).

Cost mentioned in fix

Cost: $200

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// More 300ZX (Z32) problems

Other known issues

Minor Engine -- VG30DE/DETT (All Models)

Timing Belt Failure Risk

If the timing belt breaks, the valves collide with the pistons. The engine is destroyed. There is no warning -- the belt simply snaps and the engine stops instantly with catastrophic internal damage.

Critical Engine -- VG30DE/DETT (All Models)

Oil Leaks

Oil seepage and dripping from multiple points -- valve cover gaskets, rear main seal, oil pan gasket, timing cover, turbo oil lines (TT), power steering lines, and various sensors.

Minor Engine -- VG30DE/DETT (All Models)

Overheating

Temperature gauge climbs, particularly in traffic or on hot days. Coolant loss. Steam from under the bonnet.

Common Twin-Turbo System (VG30DETT Only)

Vacuum Line Deterioration

Boost fluctuations, poor throttle response, check engine light, erratic idle, boost creep (boost exceeding target), or inability to make boost.

Critical Twin-Turbo System (VG30DETT Only)

Turbocharger Wear

Excessive turbo whine, metallic grinding or rattling from the turbos, blue smoke under boost (oil passing through worn seals), or reduced boost pressure.

Critical Twin-Turbo System (VG30DETT Only)

Power Steering Line Fire Risk

Power steering fluid leaks onto the hot exhaust manifold or turbo housing. In extreme cases, the fluid ignites.

View all 15 300ZX (Z32) problems