Underbody and rear beam corrosion
Attaches to FZ at chassis level · Body & corrosion · carried by 2 variants across 1 chassis
Overview
Underbody and rear beam corrosion is a common fault recorded against FZ at chassis level, typically from 120–220k km. It shows up as flaking rust on the rear beam, the subframe and the fuel and brake lines, sometimes with an advisory already on the record. Where it's documented, the repair runs €200–€900 (cleaning and treatment at the cheap end, a replacement beam or lines at the dear end, costs dated 2026-07), and it can be checked before you buy. 2 variants across 1 chassis in this database inherit it.
What happens
Symptom. Flaking rust on the rear beam, the subframe and the fuel and brake lines, sometimes with an advisory already on the record.
Cause. Protection underneath was thin for cars sold into salted climates, and the beam and its mounts hold moisture. The mechanicals outlast the structure here, which inverts the usual buying advice.
How to check it
Static checks
Get the car on a ramp or at least look underneath with a torch, paying attention to the rear beam, its mounting points and the brake lines. This matters more than anything under the bonnet on these.
Engine off, ideally on a lift.
Every variant that carries this
| Variant | Chassis | Body | Years | Risk | Good buy | Cost as % of good buy |
|---|---|---|---|---|---|---|
| 1.2 K12B | FZ | hatchback | 2010–2017 | R1 | €5,350 | 10% |
| 1.3 DDiS D13A | FZ | hatchback | 2010–2015 | R3 | €5,100 | 11% |
The last column is the point. The same repair is an inconvenience on one variant and a reason to scrap the car on another. A failure costing a quarter of the vehicle's value changes the purchase decision regardless of how rare it is.