Car Model Guide/ Issues/ Fuel pump wear and injector contamination

Fuel pump wear and injector contamination

Attaches to QYBA at engine level · Fuel · carried by 2 variants across 2 chassis

Overview

Fuel pump wear and injector contamination is a occasional fault recorded against QYBA at engine level, typically from 120–220k km. It shows up as hard starting, a loss of power under load, and in the worst case a car that stops and won't restart. Where it's documented, the repair runs €800–€3,000 (pump and injectors, sometimes the full fuel system, at a specialist, costs dated 2026-07), and it can be partly checked before you buy. 2 variants across 2 chassis in this database inherit it.

€800 – €3,000
pump and injectors, sometimes the full fuel system, at a specialist · costs dated
Likelihoodoccasional
Typical onset120–220k km
Detectablepartially
Walk awayno
Evidencedocumented

What happens

Symptom. Hard starting, a loss of power under load, and in the worst case a car that stops and won't restart.

Cause. The high-pressure pump is lubricated by the diesel passing through it, so wear inside the pump can shed fine metal into the fuel system and damage the injectors. Poor fuel and neglected filter changes both accelerate it, and once debris is circulating the repair covers the whole system.

How to check it

Paperwork

Ask for the fuel filter record and any fuel-system work, then scan for fuel-pressure faults. A car with no filter history should be priced as a risk.

On these cars the folder is most of the value.

FueloccasionalPartly detectableevidence: documented120220k km

Every variant that carries this

VariantChassisBodyYearsRiskGood buyCost as % of good buy
1.8 TDCi QYBAMk4hatchback2007–2012R3€1,700112%
1.8 TDCi QYBAMk4 Estatewagon2007–2012R3€1,800106%

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.