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MOTRS

356

1948-1965 / Coupe / Cabriolet / Speedster / Germany

All 356 problems All workshop issues
Critical Electrical

Wiring Insulation Degradation

Symptoms

Intermittent electrical faults, blown fuses, dead circuits, and, in the worst case, electrical fires. The cloth or rubber insulation on the original wiring harness becomes brittle and cracks, exposing bare copper conductors.

Cause

60+ years of heat cycling, particularly in the engine bay where temperatures are high. The original insulation materials were not designed for this longevity.

Fix

A complete rewiring harness is the proper solution.

YnZ's Yesterdays Parts and other specialists produce exact reproduction harnesses.

Cost: $1,500-$3,000 for the harness plus $2,000-$4,000 for installation.

Partial repairs (replacing individual damaged wires) are a temporary fix.

Cost mentioned in fix
Cost: $1,500-$3,000 for the harness$2,000-$4,000 for installation

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Other known issues

Minor Electrical

6-Volt System Limitations

Dim headlights, slow starter cranking (especially in cold weather), difficulty running modern accessories (radio, USB charger).
Minor Body and Structure

Floor Pan Corrosion

The floor pans develop rust, perforation, and structural weakness. In severe cases, you can see the road through the floor. The driver's footwell and the area around the pedal box are particularly vulnerable.
Minor Body and Structure

Heater Channel Rot

The sills (rocker panels) that run along each side of the car are actually heater channels, hollow box sections that carry warm air from the engine compartment to the cabin. They corrode from the inside out, and by the time you see external rust, the structural integrity is already compromised.
Critical Body and Structure

Battery Box Corrosion

The metal surrounding the battery in the front compartment corrodes through from acid exposure. The corrosion spreads to adjacent panels and structural members.
Minor Body and Structure

Longitudinal Member (Helly) Corrosion

The main longitudinal structural members that run beneath the floor develop rust and lose structural integrity. These members carry the suspension loads and are critical to the car's structure.
Common Engine

Oil Leaks

Oil weeping or dripping from the pushrod tube seals, rocker cover gaskets, case halves, main seal, and oil cooler connections. A warm 356 engine will have oil residue on virtually every surface.
View all 15 356 problems