Audi 55 TFSI e

The EA839 has a design weakness in the water pump: an internal leak draws coolant into the vacuum system. This can lead to catastrophic engine damage.

Symptoms: Coolant level drops with no visible leak; P0299 fault code; coolant residue on left cylinder head; overheating warning.

The Q7/Q8 TFSI e high-voltage battery (build date 08/2019–07/2024) can overheat during charging and cause a fire. Recall code 93QQ, approx. 18,650 vehicles worldwide affected.

Symptoms: High-voltage battery warning message; charging interrupted; Audi recommends not charging until software update.

The PHEV gearbox installed in the Q7/Q8 TFSI e is the heavily loaded large variant. Defects in the clutch, mechatronic unit and hydraulic control lead to costly repairs.

Symptoms: Shift jerk on pull-away; hesitation when downshifting; gearbox warning message; in worst case complete failure.

After around 100,000 km, catalytic converters in the EA839 can crumble. Ceramic dust enters the cylinders and causes severe engine damage. In PHEV use, cold starts after electric-only phases accelerate wear.

Symptoms: Metallic clattering from exhaust area; engine power loss; increased fuel consumption.

The EA839 3.0 TFSI shows characteristic timing chain rattle on cold start from missing or faulty check valves in the oil channels. The chain tensioner takes too long on initial pressure build-up.

Symptoms: Clear metallic rattling on cold start that subsides after 1–3 seconds; in advanced cases also with warm engine.

Some EA839 variants tend to elevated oil consumption of up to 0.5 l/1,000 km. In PHEV operation with frequent cold starts, wear accelerates.

Symptoms: Oil level drops noticeably between services; oil burn smell; blue smoke under load.

The high-voltage battery in the Q7/Q8 TFSI e loses capacity through ageing. In the heavier SUV, the range loss is even more noticeable than in smaller PHEVs.

Symptoms: Electric range well below WLTP; below 20 km in winter.

The Q7/Q8's electrical auxiliary load is significant. After long electric-only driving with a depleted HV battery, the 12V battery can become discharged.

Symptoms: Warning message 'Battery weak'; control units fail; vehicle will not start.

Faulty sensors in both front doors can affect side airbags, head airbags and belt tensioners. RAPEX notification INFO/00089/21, April 2021. Free repair at authorised dealer.

High-voltage battery cell modules can overheat when charging and cause a vehicle fire. KBA action 93QQ affects Q8 PHEV (60 TFSI e) from production period 08/2019–07/2024. Software update as fix, approx. 60 minutes workshop visit.

Oil can leak from the automatic gearbox cooling lines. Gearbox oil on the road increases accident risk. NHTSA campaign 20V272000, 531 vehicles affected.

On Q8 models from 2019–2021 (action 42L1) an incorrectly torqued rear axle nut can alter wheel alignment and affect driving stability. Free repair at dealer.

The Q8 4M air suspension shows typical weaknesses on residual pressure hold valves (approx. 50 € part) and air bags. Warning light illuminates, vehicle drops on one axle, compressor runs continuously to the point of overheating.