Citroen C4 Cactus common problems and MOT failures

What usually goes wrong with a Citroen C4 Cactus?

Known faults reported by owners, mechanics and UK buying guides, in our own words. Most apply to certain years or engines only, so check which the car has.

• Timing belt that runs in oil (PureTech petrol)

  Cars registered 2014–2021 · 1.0 and 1.2 PureTech petrol

  The 1.0 and 1.2 PureTech petrol engines use a timing belt that runs in the engine oil (a “wet belt”). It can break down early and shed rubber that blocks the oil supply, which can wreck the engine. Some also burn too much oil. Stellantis now covers earlier engines for belt and oil-burning problems for up to 10 years or 112,000 miles, as long as the car has been serviced on schedule.

  At the viewing: Ask for a full service history showing the right oil, and when the belt was last checked or changed. Check the oil level on the dipstick, and that no oil-pressure or engine warning light stays on.

  Source: Parkers: Stellantis wet belt compensation, and the cars at risk, Stellantis: compensation policy for earlier PureTech 1.0 and 1.2 engines (7 May 2025)

Common Citroen C4 Cactus MOT failures to check

Parts flagged at MOT well above the usual rate for cars the same age, for each fuel on its own. From the DVSA’s results for every MOT done in Great Britain during 2023–2025.

Petrol

• Exhaust system

  up to 13× usual

  Stands out on cars registered in 2015, 2016, 2017, 2018, 2019 and 2020.

  Rough price £100–£500 (pipe or section) ClickMechanic

  At the viewing: Listen for blowing or rattling from underneath at idle, and look for black soot around joints.

• Wipers

  up to 3.1× usual

  Stands out on cars registered in 2015, 2016, 2017, 2018, 2019 and 2020.

  Rough price £15–£60 our estimate

  At the viewing: Test the wipers and washers on every speed.

• Number plate lights

  up to 4.5× usual

  Stands out on cars registered in 2015, 2016, 2017, 2018 and 2019.

  Rough price £5–£40 our estimate

  At the viewing: Check the number plate lights work and the plates are clean and legal.

• Brake discs

  up to 2.1× usual

  Stands out on cars registered in 2018, 2019, 2020 and 2021.

  Rough price £150–£350 our estimate

  At the viewing: Look through the wheel at the brake disc: a deep lip at the edge or heavy scoring means they're worn. Feel for judder when braking.

• Headlights

  up to 3.6× usual

  Stands out on cars registered in 2016, 2018 and 2019.

  Rough price £40–£400 our estimate

  At the viewing: Check both headlights on dipped and full beam, and look for cloudy or cracked lenses.

• Drive shaft (CV) joints

  up to 4.9× usual

  Stands out on cars registered in 2016 and 2017.

  Rough price £60–£350 our estimate

  At the viewing: Drive slowly on full steering lock in both directions and listen for clicking. Look for split rubber boots behind the front wheels.

Diesel

• Exhaust system

  up to 65× usual

  Stands out on cars registered in 2015, 2016, 2017, 2018, 2019 and 2020.

  Rough price £100–£500 (pipe or section) ClickMechanic

  At the viewing: Listen for blowing or rattling from underneath at idle, and look for black soot around joints.

• Number plate lights

  up to 5.5× usual

  Stands out on cars registered in 2015, 2016, 2017, 2018 and 2019.

  Rough price £5–£40 our estimate

  At the viewing: Check the number plate lights work and the plates are clean and legal.

• Drive shaft (CV) joints

  up to 7.5× usual

  Stands out on cars registered in 2015, 2016, 2017 and 2018.

  Rough price £60–£350 our estimate

  At the viewing: Drive slowly on full steering lock in both directions and listen for clicking. Look for split rubber boots behind the front wheels.

• Wipers

  up to 2.7× usual

  Stands out on cars registered in 2016, 2017, 2018 and 2019.

  Rough price £15–£60 our estimate

  At the viewing: Test the wipers and washers on every speed.

• Suspension arm bushes and joints

  up to 2.6× usual

  Stands out on cars registered in 2015, 2017 and 2018.

  Rough price £120–£180 (one arm) ClickMechanic

  At the viewing: Listen for clunks over bumps and feel for the steering wandering. Worn arm bushes show as cracked rubber near the wheels.

• Engine oil leaks

  up to 3× usual

  Stands out on cars registered in 2015 and 2016.

  Rough price £80–£600 our estimate

  At the viewing: Look under the engine and where the car is usually parked for fresh oil. Ask whether the leak has been looked at.

Citroen C4 Cactus MOT pass rate by year

Of the years since 2005 with plenty of MOT tests, the 2021 Citroen C4 Cactus did best (88% passed first time, 1 point above all 2021 cars) and the 2015 did worst (60%, 14 points below all 2015 cars). Older cars fail more, so compare each year with all cars registered the same year.

Questions to ask the seller before buying a Citroen C4 Cactus

Ask before you travel to see it. A seller who knows the car will have answers, and receipts.

1. When was the timing belt last checked or changed, and has it had the right oil at every service? Is the car still within Stellantis’ extended PureTech cover?
2. Any recent work on the exhaust system? (Flagged at MOT 19.5× as often on the Citroen C4 Cactus as on other cars the same age.)
3. Any recent work on the number plate lights? (Flagged at MOT 4.7× as often on the Citroen C4 Cactus as on other cars the same age.)
4. Any recent work on the wipers? (Flagged at MOT 3× as often on the Citroen C4 Cactus as on other cars the same age.)
5. Can I see the service history and receipts for any big jobs?