Citroën C4 Aircross 1

Strongest variant of the 1.6 HDi (80 kW) with VGT turbocharger and more elaborate exhaust aftertreatment than the lower-output versions. The oil feed line to the turbocharger clogs with soot particles in the oil — regular oil changes every 15,000 km are mandatory. Injector seals and the EGR valve are further typical wear items. DPF is problematic on short trips. On long-distance duty, a punchy and economical everyday diesel.

• !! VNT turbocharger: vanes seized — most common failure from 120,000 km

  On the 109 hp DV6, seized variable VNT vanes clogged by oil sludge is the single most documented failure. PSA has issued a technical service bulletin. Without oil changes every 10,000 km, the damage typically occurs before 150,000 km.

  Symptoms: Sudden limp mode, loss of boost, whistling turbo noise, black smoke, faults P0234/P0299
  900–2,500 $
  Ad turbocharger 1.6 HDi 109PS VTGTurbo DV6C 753420Garrett GT1544V PSA 109PS
• !! Injectors seized — cylinder head damage possible from 140,000 km

  DV6-109 injectors seize in their bores with neglected servicing. Removal requires specialist tools and can take over 10 hours. In extreme cases the threaded bolt shears and the cylinder head must be replaced.

  Symptoms: Smoky cold-start smell, misfires, black soot deposit at injector, knocking noise
  500–3,000 $
  Ad fuel injector 1.6 HDi 109PS Boschfuel injectorgasket DV6Cfuel injector Extraktor PSA 1.6
• !! EGR cooler leaking — coolant ingress from 120,000 km

  The DV6-109 EGR cooler can become porous from thermal shock and let coolant into the intake tract. This leads to white smoke, coolant loss and in the worst case a hydraulic lock in the cylinder.

  Symptoms: White smoke, sweet smell from exhaust, dropping coolant level, coolant smell in cabin
  300–800 $
  Ad EGR radiator 1.6 HDi 109PSEGR radiator DV6C Citroen C4EGR-radiator PSA 1.6 109HP

+ 3 more engine weaknesses + vehicle weaknesses

Mitsubishi diesel (1.8 L DI-D, 110 kW) with aluminium block, common-rail direct injection and 16 valves. Timing chain drive, fundamentally robust and long-lived with correct maintenance. DPF regeneration is problematic on predominantly short trips — the engine rarely reaches the required operating temperature. Injectors and EGR valve are the most common wear items. Oil changes every 15,000 km to Mitsubishi specification are essential.

• !! Oil dilution from DPF regeneration from 60,000 km

  Aborted DPF regeneration in the 4N13 causes diesel to enter oil.

  Symptoms: Rising oil level, diesel smell on dipstick
  100–500 $
• !! Charge air duct failure from 80,000 km

  The 4N13 turbo charge air duct can crack.

  Symptoms: Whistling under load, power loss
  300–2,000 $
• !! EGR valve coked up, P0401 fault from 90,000 km

  The EGR valve on the 1.8 DI-D (Mitsubishi 4N13) cokes up with heavy soot deposits. The intake tract also becomes heavily contaminated. Particularly problematic on short trips. Cleaning or replacement needed every 80,000–100,000 km.

  Symptoms: Hesitation and shuddering at mid revs, fault code P0401 (insufficient EGR flow), engine warning light, increased fuel consumption.
  150–500 $
  Ad EGR valve 1.8 DI-D 4N13EGR Valve 4N13 6HZEGR valve C4 Aircross 1.8 HDiEGR 1802A172

+ 3 more engine weaknesses + vehicle weaknesses

The EP6 VTi (N12/EP6C) is the naturally aspirated variant of the Prince engine without direct injection, making it less susceptible to intake valve carbon build-up than the THP. The early production chain tensioner issue is known; PSA improved the tensioner from 2012. Regular oil changes every 10,000 km are mandatory.

• !! Timing chain rattle due to tensioner wear from 80,000 km

  Early EP6 VTi engines (pre-2012) suffer from a weak hydraulic chain tensioner that rattles on cold starts. The single-row timing chain stretches when tensioner pressure drops, causing valve timing to shift. PSA documented oil leaks from the chain tensioner between April 2010 and April 2011.

  Symptoms: Rattling or chattering from the timing chain area for several seconds after cold start, occasionally also at operating temperature when oil level is low
  300–900 $
  Ad chain tensioner EP6 VTitiming chain tensioner N12 EP6Ctiming chain kit 1.6 VTi PSA0829.F3
• !! Chain tensioner failure — timing chain rattles from 100,000 km

  The hydraulic chain tensioner on the EP6 VTi is a known weakness at PSA and BMW. The tensioner loses oil pressure when stationary, causing the chain to rattle on cold start and risk jumping a tooth.

  Symptoms: Loud rattling on cold start that disappears after a few seconds, engine check light, camshaft position sensor fault code
  300–900 $
  Ad chain tensioner EP6 VTiSteuerchain tensioner 1.6 VTi PSA BMWchain tensioner 0829.S3
• !! Torn oil separator diaphragm in valve cover from 70,000 km

  The oil separator (PCV diaphragm) in the EP6 valve cover tears and routes unfiltered oil into the intake tract. This leads to elevated oil consumption, coking of the intake valves and visible oil in the intake hose.

  Symptoms: Elevated oil consumption without visible external leak, oil in intake hose, blue smoke after cold start, power loss from contaminated intake valves
  80–300 $
  Ad valve cover EP6 oil separatorPCV diaphragm EP6Cvalve cover gasket 1.6 VTi0249.L1

+ 3 more engine weaknesses + vehicle weaknesses