RX-7 (SA/FB)

1978-1985 / Coupe / Japan

All RX-7 (SA/FB) problems All workshop issues

Critical Engine, Rotary-Specific Issues

Coolant Seal (O-ring) Failure

Symptoms

Coolant leaks into the combustion chamber (white smoke from exhaust, coolant loss without external leak) or coolant leaks externally from the engine block mating surfaces. The engine overheats.

Cause

The rubber O-rings that seal the coolant passages between the rotor housings and the side housings (end plates) harden and lose their sealing ability with age and heat cycling. This is an age-related failure, the O-rings eventually go regardless of maintenance.

Fix

Engine must be disassembled to replace the O-rings.

Since the engine is apart, a full seal kit and rebuild is standard practice.

Cost: $2,500-4,000 including all seals.

Cost mentioned in fix

Cost: $2,500-4,000 including all

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Other known issues

Minor Engine, Rotary-Specific Issues

Apex Seal Wear and Failure

Gradual loss of compression, reduced power output, difficulty starting (especially when hot), increased oil consumption, and eventually the engine won't sustain combustion. In catastrophic failure, a broken apex seal fragment can score the rotor housing surface, requiring housing replacement.

Minor Engine, Rotary-Specific Issues

Rotor Housing Scoring

Deep scratches or grooves in the chrome or Nikasil coating of the rotor housing inner surface. Reduces compression even with new apex seals. Visible during engine disassembly.

Common Engine, Rotary-Specific Issues

Oil Metering Pump Failure

The engine receives insufficient oil for apex seal lubrication. The apex seals run dry, wear accelerates dramatically, and catastrophic engine failure follows. There may be no warning, the engine simply starts losing compression faster than normal.

Minor Engine, Rotary-Specific Issues

Carbon Buildup

Hard carbon deposits accumulate on the rotor faces, apex seal grooves, and exhaust ports. The deposits restrict apex seal movement in their grooves, causing the seals to stick and lose their spring tension against the housing. Compression drops, power decreases, and the engine runs rough.

Minor Rust

Inner Guard Corrosion

The front inner guards corrode from trapped mud, moisture, and road debris. Rust perforates the inner guard panels, weakening the structural support for the front suspension mounts.

Minor Rust

Floor Pan Corrosion

The floor pans rust from underneath, often hidden by carpets and sound deadening. In severe cases, you can see the road through the floor. The floor provides structural rigidity to the unibody, perforated floors compromise the car's integrity.

View all 15 RX-7 (SA/FB) problems