2018 Citroen C4 Cactus petrol: common problems and MOT failures

What goes wrong more than usual on a 2018 Citroen C4 Cactus petrol?

Parts flagged at MOT more often on the 2018 Citroen C4 Cactus petrol than on all cars registered in 2018.

• Exhaust system11.3× usual
  Citroen C4 Cactus

  9% All 2018 cars

  0.8%

  Failed outright at MOT: 1.6%, against 0.2% of all 2018 cars. The rest were advisories or minor defects.

  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.

• Brake discs1.7× usual
  Citroen C4 Cactus

  16.7% All 2018 cars

  9.8%

  Failed outright at MOT: 1.2%, against 0.5% of all 2018 cars. The rest were advisories or minor defects.

  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.

• Wipers3.1× usual
  Citroen C4 Cactus

  8.6% All 2018 cars

  2.8%

  Failed outright at MOT: 6%, against 1.8% of all 2018 cars. The rest were advisories or minor defects.

  Rough price £15–£60 our estimate

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

• Number plate lights4.2× usual
  Citroen C4 Cactus

  5.9% All 2018 cars

  1.4%

  Failed outright at MOT: 1.9%, against 0.5% of all 2018 cars. The rest were advisories or minor defects.

  Rough price £5–£40 our estimate

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

• Headlights3.6× usual
  Citroen C4 Cactus

  3.6% All 2018 cars

  1%

  Failed outright at MOT: 3.6%, against 0.9% of all 2018 cars. The rest were advisories or minor defects.

  Rough price £40–£400 our estimate

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

Common 2018 Citroen C4 Cactus petrol MOT failures and advisories

The share of 2018 Citroen C4 Cactus petrol MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

• Tyres
  31% of testsRough price £70–£150

  At the viewing: Check the tread on all four tyres, including the inside edges, and look for cracks or bulges.

• Brakes
  20% of testsRough price £150–£350

  At the viewing: Look for a lip on the disc edges and feel for judder or pulling when braking firmly from about 40mph.

• Lights and electrics
  15% of testsRough price £10–£80

  At the viewing: Ask a friend to check every light, including brake lights and indicators, while you operate them.

• Wipers, windscreen and mirrors
  12% of testsRough price £15–£250

  At the viewing: Check for chips in the driver's view, and test the wipers and washers.

• Suspension
  10% of testsRough price £120–£400

  At the viewing: Listen for knocks over speed bumps, and look behind each front wheel for a snapped coil spring.

• Exhaust and emissions
  9% of testsRough price £100–£1,200

  At the viewing: Look for black soot in the tailpipe, listen for blowing from the exhaust and check for an engine warning light.

Known faults on the 2018 Citroen C4 Cactus petrol

Reported by owners, mechanics and buying guides for this model and age. Check which engine the car has, as some apply to one engine only.

• Timing belt that runs in oil (PureTech petrol)

  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)

Questions to ask the seller before buying a 2018 Citroen C4 Cactus petrol

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 11.3× as often on the 2018 Citroen C4 Cactus petrol as on other cars the same age.)
3. Any recent work on the brake discs? (Flagged at MOT 1.7× as often on the 2018 Citroen C4 Cactus petrol as on other cars the same age.)
4. Any recent work on the wipers? (Flagged at MOT 3.1× as often on the 2018 Citroen C4 Cactus petrol as on other cars the same age.)
5. Can I see the service history and receipts for any big jobs?