MGB GT V8

1973-1976 / Coupe / United Kingdom

All MGB GT V8 problems All workshop problems

Common Body and Structure

Boot Floor and Battery Box Corrosion

Symptoms

The boot floor softens and perforates, particularly around the battery box (in cars with the twin 6-volt battery setup in the boot). Acid weeps from the batteries and eats through the floor pan.

Cause

Battery acid is highly corrosive and the factory didn't provide adequate protection. Even with a sealed battery, condensation and minor spills accumulate. Road spray attacks the underside simultaneously.

Fix

New boot floor repair sections and battery box panels are available.

Clean back to solid metal, treat, and weld in new panels.

Fit a fibreglass battery tray or line the area with acid-resistant paint after repair.

Cost: $300--800 depending on extent.

Cost mentioned in fix

Cost: $300

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// More MGB GT V8 problems

Other known issues

Minor Body and Structure

Sill Corrosion (Inner and Outer)

The outer sill skin bubbles, softens, and eventually perforates. In advanced cases, the outer sill crumbles when prodded. The inner sill -- the structural member -- rots from inside the box section and loses its load-bearing capacity.

Critical Body and Structure

Floor Pan Corrosion

Soft or perforated floor pans, particularly in the footwells and under the seats. Wet carpet is a telltale sign. In severe cases, you can see the road through the floor.

Minor Body and Structure

A-Post Corrosion

Rust at the base of the windscreen pillars where they meet the scuttle panel. This area can be invisible until advanced.

Minor Body and Structure

Door Skin Corrosion

Rust along the bottom edge of each door, working upward from the inside.

Minor Body and Structure

Rear Spring Hanger Corrosion

The mounting points for the leaf spring rear suspension corrode, crack, or tear away from the body.

Critical Engine

Bottom End Bearing Wear

Low oil pressure at idle when warm (below 15 psi). A deep rumbling or knocking sound from the lower engine, particularly at idle and on acceleration. This is the main and big-end bearings wearing out.

All MGB GT V8 problems