- Engine / equipment
- 3.0 TFSI supercharged V6 (EA837): S4 B8, S5 8T from 2011, A6/A7 C7 3.0 TFSI, Q5 3.0 TFSI and SQ5 TFSI
- Period mentioned
- 2009–2018
- Symptoms
- Coolant loss, sweet smell, unstable temperature; misfires; some oil consumption; on some S5s, chain noise from 60,000–80,000 km.
- Possible cause described
- Thermostat and water pump with plastic housings that crack with age, and a crankcase ventilation (PCV) valve that Audi revised to reduce oil consumption. Chain wear is reported on 2010–2014 S5s.
- Check for the garage
- Look for leaks at the thermostat and water pump, read misfire codes, run an oil consumption test and listen for the chain on a cold start.
- Cost cited in the source
- Thermostat or water pump: a few hundred euros (estimate); chain with tensioner and guides: €2,500–4,000A rough figure from the original database, not an up-to-date quote.
Mileage cited in the database: from 60,000 km. This is not a maintenance interval and does not predict a failure.