Question 1

Fault in the heater control valve (HCV)

Accepted Answer

The electromagnetically controlled valve regulating the flow of coolant to the heater radiator is a chronic failure in this generation. When it fails, the system blows only extremely hot air or only cold air, regardless of the temperature selected on the panel.

Question 2

Instability in the idle caused by the IAC valve being impregnated

Accepted Answer

The 1.25 Zetec‑S engine frequently accumulates carbon deposits on the idle air control valve (IAC). This results in abrupt RPM fluctuations, irregular idle and sudden engine stalls when disengaging a gear during deceleration.

Question 3

Leak in the valve cover gasket and oil accumulation in the spark plug wells

Accepted Answer

With engine ageing, the valve cover gasket dries out and loses its seal, allowing engine oil to leak into the spark plug wells. Contamination of the spark plug wires and plugs by oil causes misfires and hesitation under acceleration.

Question 4

Corrosion in the rear wheel arches and wheel well liners

Accepted Answer

The factory corrosion protection for this generation of Fiesta is limited. Over time and with exposure to moisture, severe rust develops in the lower inner wheel arches, rear wheel well liners and jack‑point supports, which can cause failure in the mandatory periodic inspection (IPO).

Ford FiestaFiesta Mk4

Known issues and common problems

Ford FiestaFiesta Mk4

Known issues and common problems

Fault in the heater control valve (HCV)at 80000 km · 1 solutionsMedium

Instability in the idle caused by the IAC valve being impregnatedat 100000 km · 1 solutionsMedium

Leak in the valve cover gasket and oil accumulation in the spark plug wellsat 110000 km · 1 solutionsMedium

Corrosion in the rear wheel arches and wheel well linersat 130000 km · 1 solutionsHigh