Common Problems with the
2006–2009 Caterham Seven (Ford Sigma / Duratec)

We've identified 2 known issues that can affect the 2006–2009 Caterham Seven (Ford Sigma / Duratec). 1 of these are serious faults that could be expensive to repair.

Known Issues

Serious

Moderate

Minor

The 2006–2009 period has an average number of reported issues compared to other Caterham Seven (Ford Sigma / Duratec) year periods.

All Known Issues

De Dion Tube Fatigue

SeriousSuspension & Chassis

The De Dion tube can develop hairline cracks near the welds on cars used heavily on track or with stiff suspension.

Most affected: All De Dion equipped models

Estimated cost: £400–£700Affects: 2006–2025

Typical symptoms

•Vague rear-end handling
•Cracks visible in paint/coating of the tube

What to inspect before you buy

✓Thoroughly clean and inspect the De Dion tube welds.
✓Look for "fretting" marks (rust dust) near joints.

Engine Mount Cracking

ModerateEngine

The vibrations from the Duratec engine, especially in higher states of tune, can crack the engine mounting brackets.

Most affected: 420, 485, and 620 models

Estimated cost: £150–£400Affects: 2006–2025

Typical symptoms

•Excessive engine movement
•New vibrations through the chassis

What to inspect before you buy

✓Inspect engine mounts for cracks or perished rubber.

Buying Tips for the 2006 Caterham Seven (Ford Sigma / Duratec)

✓Check the dry-sump system (if fitted) for leaks and oil level accuracy.
✓Ensure the cooling fans trigger correctly; the Ford engines run hot in traffic.
✓Inspect the rear differential for oil leaks, particularly around the input seal.

2010–2025 Caterham Seven (Ford Sigma / Duratec)