2018 Citroen C4 Problems: 2 Issues Every Owner Should Know
2018 model year · 155+ owner reports · Updated May 2026
According to Au7o's analysis of 155+ owner reports, the 2018 Citroen C4 has 2 documented known issues, with 1 rated critical. The most serious is Diesel DPF Regeneration Issues ($300-$2,500 repair). Across all issues, repair costs range from $150 to $2,500. DIY maintenance guides at au7o.io.
All 2 Known Issues
On the 2004-2026 Citroen C4, the C4 diesel models suffer from the common PSA DPF regeneration problems, with the additive-based system requiring regular Eolys fluid top-ups. Short journey use prevents passive regeneration from completing.
Common Symptoms
- DPF warning light
- Engine limp mode
- Power loss
- Increased fuel consumption
How to Fix
Top up Eolys additive, force DPF regeneration via diagnostic tool, and advise regular motorway driving. Severely blocked filters require professional cleaning or replacement.
On the 2004-2021 Citroen C4, the C4 diesel EGR valve accumulates carbon deposits that cause it to stick open or closed. The blocked EGR increases exhaust emissions, causes rough idle, and can trigger the engine management warning light.
Common Symptoms
- Rough idle
- Black smoke from exhaust
- Loss of power
- Engine management light
How to Fix
Remove and clean the EGR valve with carb cleaner and a wire brush. Replace if the valve is damaged or does not move freely after cleaning. Update ECU software for improved EGR control.