2018 Audi A4 problems

• 3.0 TDI EA897 evo, Euro 6 (CRTC, CRTD, CRTE, CRTF, CZVA, CSWB, DDXB and others; 2014-2020)

  163–272 hp · CRTC, CRTD, CRTE, CRTF, CZVA, CZVB, CZVC, CZVE, CZVF, CSWB, CVZA, CVVB, DDXA, DDXB, DDXC, DDXE

  The CRT and CZV series from 2014 to early 2017 have an Audi bulletin for possible camshaft breakage: check the engine number and whether they were replaced. The 200 kW A6 and A7 also went through the KBA recall.^[2][3][4][5]

  With caution

• 3.0 TDI EA897 evo2 (DCPC, DDVC, DDVB, DHXA, DHXC, DENA, DEWA, DEWB; 2017-2021)

  231–349 hp · DCPC, DDVC, DDVB, DDVE, DHXA, DHXC, DENA, DEND, DEWA, DEWB

  A 2024 guide to the A6 C8 reports no current complaints about camshafts or the oil pump in the EA897 family, although there is little history and it keeps the general warning that a chain failure costs several thousand euros.^[6]

  Buy

Faults that affect 2018 cars

• High severityFrequency: CommonCoolingFailing water pump and cooling system leaksOn the 3.0 TDI the water pump can fail and, from 2010, overheat to the point of damaging the engine (the A6 C6 guide cites a service action). Owners also cite coolant leaks from hoses, the regulating valve and the cooler.
• High severityFrequency: OccasionalTimingTiming chain stretch and tensioner wearOn the 3.0 TDI V6 the timing chain is at the gearbox end and its tensioner can lose tension: it rattles on a cold start and, if the chain stretches, the timing goes out and the engine is at risk. Replacing it means opening the engine and costs several thousand euros.
• High severityFrequency: OccasionalInjectionInjector wear (needle seat) and injection faultsGerman guides point to wear of the needle seat of the 3.0 TDI injectors: they stop closing properly, diesel drips into the cylinder and dilutes the oil. Smoke from the exhaust can be the warning, and reports on the 313 hp twin-turbo repeat injection faults.
• Medium severityFrequency: CommonEmissions controlControl unit software with a prohibited emissions strategy (NOx and AdBlue)Germany's KBA ordered a software update for the Euro 5 and 6 3.0 TDI V6 engines from Audi, VW and Porsche: a warm-up strategy that reduced NOx only on the test bench and, on the 200 kW A6 and A7, limited AdBlue dosing. The update is free.Repair: €0

• 3rd generation, with electrification (from 2018)

  · 8HP51, 8HP76, 8HP95, 850RE

  There is less accumulated mileage and fewer accounts than with the earlier versions, and on plug-in hybrid models there are added electronic warnings shared between the engine and the gearbox that complicate diagnosis. There are no known systemic defects, but there is less track record to confirm it.^[8]

  With caution

Faults that affect 2018 cars

• High severityFrequency: OccasionalElectronicsMechatronic failure as the gearbox ages (sometimes with reverse)Yes, although in a minority of cases: there are documented ZF 8HP mechatronic failures on BMW after 120,000-130,000 km, costing €1,400 to €3,500, and also control unit or electronic selector faults on Audi and Land Rover.Repair: €1,400–€3,500
• Medium severityFrequency: CommonTransmissionJerking and hesitation when changing gear, sometimes needing reprogrammingYes: on BMW, Audi, Jaguar and Alfa Romeo there are accounts of jerking, hesitation or harsh shifts with the ZF 8HP. It is usually due to ageing oil or the calibration of the mechatronics, and the dealer often fixes it -not always first time- by reprogramming the gearbox control unit.
• Medium severityFrequency: OccasionalLubricationOil leaks from the gearbox gaskets or sumpYes: on the BMW 1 Series and the Jaguar F-Pace there are accounts of oil leaks from the ZF 8HP gearbox gaskets, in one case already at 40,000 km. If it is not repaired soon, the loss of pressure can speed up internal wear and lead to the jerking or mechatronic failure of the related faults.Repair (garage): €1,000–€2,000

• 2.0 TSI/TFSI Gen 3B / evo, with added indirect injection (2016 onwards, 190-320 hp)

  190–320 hp · CHHA, DKFA, DLBA, CJXE, CJXA, CJXB

  The added indirect injection reduces the carbon build-up problem and the documented oil consumption is lower. It is still worth checking the thermostat housing/water pump and the PCV valve, which are common to the whole family.^[9][10][12]

  Buy

Faults that affect 2018 cars

• Medium severityFrequency: CommonCoolingThermostat housing leak and water pump failureSince Volkswagen integrated the water pump impeller into the thermostat housing, this plastic part leaks coolant over time; on the oldest units, with a separate belt-driven pump, failures of the pump itself are also documented.
• Low severityFrequency: OccasionalLubricationPCV valve (crankcase ventilation) failureThe PCV valve returns to the intake manifold the oil and combustion vapours that build up in the crankcase. If it sticks closed or open, it causes a rough idle, misfires or oil leaks from the seals.Repair (garage): €60–€250

• 2.0 TDI EA288 (from 2012)

  110–240 hp · CRBC, CUNA, CUPA, CRLB, CRMB, DFEA, DFEB, DFFA, DFGA, DDAA, DFCA, CUAA

  Caradisiac picks it as the best diesel in the third-generation Audi A3. Its most cited fault is coolant loss from water pump leaks, easy to keep an eye on before buying.^[14]

  Buy

Faults that affect 2018 cars

• Medium severityFrequency: CommonCoolingCoolant loss from the water pump or the coolersMany 2.0 TDI engines lose coolant. On the 150 hp EA288 the water pump is usually the culprit and, more rarely, the cylinder head; on the 140 hp EA189 the typical causes are the oil cooler or the EGR cooler.
• Low severityFrequency: RareTurboHissing when accelerating from damaged hoses or intercooler on the Transporter T6 2.0 TDIOn the Transporter T6 2.0 TDI (2015-2019) a hissing sound can be heard when accelerating, caused by loose or damaged hoses or a crack in the intercooler. Often there is no loss of power and no warning light; oil stains reveal the crack.

• 3.0 TFSI turbo (EA839: CZSE, DR, CWGD; 2016 onwards)

  330–354 hp · CZSE, DR, CWGD

  We have not found any documented faults of its own in open sources; the German A6 C8 guide says this V6 has not given problems so far, although with few years of use and no high-mileage data.^[6]

  Buy

• 2.9 TFSI twin-turbo (EA839: DECA, DKMB; 2016 onwards)

  330–450 hp · DECA, DKMB

  No documented faults of its own in open sources (the A6 C8 guide only says the EA839 has not attracted attention), but these are very recent versions with sporty use; check the maintenance history.^[6][15]

  Buy

There are no documented Audi 3.0 TFSI V6 faults that affect 2018 cars.

• Critical severityFrequency: OccasionalElectrical systemRisk of short circuit and fire due to moisture in electrical componentsAudi recalled A4 B9 units built between May 2017 and March 2020 because moisture can seep into an electrical component and cause a short circuit, with a risk of the vehicle catching fire.Repair: €0
• High severityFrequency: OccasionalAirbags and safetySeveral one-off campaigns on seat anchorage and the front airbag (2018-2021)Between 2018 and 2021, Audi ran several one-off campaigns on the A4 B9, each on a different and limited build batch: the front seat anchorage, the airbag control unit, a screw on the passenger airbag module and the windscreen adhesive that supports it.Repair: €0
• Low severityFrequency: CommonElectronics and infotainmentMMI system restarts, freezes and loss of connectivityA specialist reliability review, analysing 49 owner reports, points to MMI electronic problems (restarts, freezes and loss of Bluetooth and connected services) as the most repeated complaint about the A4 B9.