UK Buyer Reliability Guide3 Known Faults Documented

Ford Ka Mk2 (B420) Common Problems & Reliability

The second-generation Ford Ka (Mk2) marked a significant departure from its predecessor, sharing its core platform and mechanical underpinnings with the ubiquitous Fiat 500. Manufactured in Poland alongside the Fiat, it retains a distinctively Ford exterior while benefiting from improved refinement and safety. For UK buyers seeking a cheap-to-run, ULEZ-compliant city car with incredibly low insurance groups, it remains a highly logical purchase. Mechanically, the Mk2 is generally dependable, particularly the Fiat-derived 1.2-litre FIRE petrol engine which is simple, frugal, and easy to maintain. However, buyers must be vigilant regarding the gearbox and suspension. The manual gearbox is prone to premature bearing failure, manifesting as a noticeable whine that eventually requires an expensive rebuild. Additionally, water ingress at the front strut tops frequently causes the mounts to rust and fail, a known weak point that can be mitigated with inexpensive aftermarket dust covers. Despite being much younger than the rust-prone Mk1, the Mk2 is not entirely immune to corrosion and electrical gremlins. Rear axle beams and inner sills can suffer significant rust, making a thorough underbody inspection vital. Electrically, the Electric Power Steering (EPS) motor and airbag modules are known failure points. Treat any Ka Mk2 purchase as an assessment of condition over mileage; a well-maintained example is a brilliant urban runabout, but ignored faults can quickly eclipse the car's value.

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Generation Periods
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Known Issues
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Critical Faults
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Moderate Issues

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Detailed fault breakdown, symptoms, and estimated repair bills by production year.

Most Common Ford Ka Mk2 (B420) Faults & Repair Costs

High Risk

Rear Axle and Sill Corrosion

Est. Cost£250–£1,200

Despite being newer than the Mk1, the Ka Mk2 can still rust badly around the rear axle, inner sills and wheel-arch seams, and structural repairs quickly outweigh the value of a cheap car.

Warning Signs:

Rusty rear axle beam, Bubbling around rear arches, Repeated MOT corrosion advisories

High Risk

Electric Power Steering Column Failure

Est. Cost£250–£600

The column-mounted electric steering can lose assistance intermittently or permanently, often after low-voltage events or torque-sensor wear.

Warning Signs:

Heavy steering at parking speed, EPS warning light, Assistance returns after restarting the engine

Moderate Risk

Heater Blower Resistor and Tailgate Wiring Faults

Est. Cost£80–£250

Ageing blower resistors and broken wiring at the tailgate can leave the Ka with missing fan speeds, dead rear electrics or damp-related gremlins.

Warning Signs:

Heater fan only works on one speed, Boot release or rear wiper faults, Intermittent warning lights after rain

Essential Pre-Purchase Step

Buying a used Ford Ka Mk2 (B420)? Always check for hidden finance and write-off history.

Mechanical problems are only half the battle. Over 1 in 3 UK used cars checked have unpaid finance or accident write-off records that could cause you to lose the car or thousands in value.

Inspection Checklist for Ford Ka Mk2 (B420) Buyers

Inspect the rear axle, sills and inner arches carefully because rusty Mk2 Kas can look smarter on top than they are underneath.
The electric steering must feel light and consistent from cold; intermittent heaviness is rarely just a weak battery.
Run the heater fan through every speed and check the boot floor for damp, because blower-resistor and tailgate-wiring issues are common age-related faults.