Known faults for the Audi A4 (B8).

Engine / equipment

1.8 / 2.0 TSI-TFSI EA888, 2nd generation

Period mentioned

Approx. 2009–2015

Symptoms

Very high oil consumption (over 1 litre per 1,000 km), low oil warning, bluish smoke, oil-fouled spark plugs.

Possible cause described

Piston rings that are too thin carbon up and lose tension, letting oil into the combustion chamber. The crankcase ventilation (PCV) valve can also contribute.

Check for the garage

Controlled oil consumption test over 1,000 km, compression or leak-down test and a PCV valve check.

Cost cited in the source

€3,000–5,000 (new pistons and rings)A rough figure from the original database, not an up-to-date quote.

Sources from the original database

Engine / equipment

1.8 / 2.0 TSI-TFSI EA888, 1st and 2nd generation

Period mentioned

Approx. 2008–2015

Symptoms

Metallic rattle for a few seconds on a cold start, engine light for camshaft/crankshaft correlation; in the worst case the engine won't start after a loud noise.

Possible cause described

The hydraulic chain tensioner (old design) loses pressure on cold starts, the chain goes slack and can jump teeth, causing valves to hit pistons.

Check for the garage

An inspection plug on the lower timing cover shows the tensioner position. Listen to a cold start.

Cost cited in the source

€1,500–4,000 (chain, guides and tensioner)A rough figure from the original database, not an up-to-date quote.

Sources from the original database

Engine / equipment

Air conditioning with clutchless compressor and N280 regulating valve (combustion VW, Audi, Seat, Cupra and Skoda from 2006)

Period mentioned

2006–2026

Symptoms

The air does not cool or cools intermittently (for example only at motorway speed), and sometimes the compressor rattles with the A/C on. Codes 01232 (N280 valve), P2612 or 00898.

Possible cause described

The compressor regulates its output with the N280 solenoid valve, its most common failure point. Audi issued technical bulletins over a manufacturing fault in this valve on Sanden compressors. Its connector can also become brittle and corrode (especially without the engine undertray), or the wiring fails.

Check for the garage

Read the codes and N280 control current with VCDS or ODIS, measure its resistance (about 10 ohms) and check the connector and wiring before replacing parts. If the valve or compressor is replaced, the whole circuit must be flushed.

Cost cited in the source

N280 valve: a cheap part (about 30 dollars) where sold separately; new compressor with circuit flush: considerably moreA rough figure from the original database, not an up-to-date quote.

Sources from the original database

Engine / equipment

Multitronic continuously variable gearbox (01J and successors) in front-wheel-drive Audis: A4 B6/B7/B8, A5 8T and A6 C5/C6/C7

Period mentioned

2000–2014

Symptoms

Judder or vibration when pulling away (especially uphill), a slipping feeling at low revs, jerky acceleration and limp mode with limited speed; sometimes a burning smell.

Possible cause described

Known failures of the variator chain and pulleys, the hydraulic and electronic control unit and the clutch pack. Audi issued service bulletins, and forums report failures even with the recommended fluid changes, although poor maintenance speeds them up.

Check for the garage

Read the gearbox codes with Audi-compatible equipment, check the fluid change history and, at a specialist, judge whether fluid and a clutch adaptation are enough or the control unit or variator needs repair. With limp mode or a burning smell, stop driving.

Cost cited in the source

A UK specialist says a judder checked early usually costs a few hundred pounds, while ignoring it can end in a full rebuild.A rough figure from the original database, not an up-to-date quote.

Sources from the original database

Engine / equipment

A4 (B8), A5 (8T) and Q5 (8R) with 75 mm hydraulic bushings

Period mentioned

2008–2014

Symptoms

Front knocking or rattling over bumps with the car warm and hot outside, especially when braking at the same time; in the cold it is not heard.

Possible cause described

Heat makes the front guide links' hydraulic bushings noisy (only the 75 mm ones). Audi describes it in bulletin 40 14 39 (February 2014) as a comfort issue that does not affect the car's handling.

Check for the garage

Note whether it only happens in hot weather and when braking over bumps. At the garage, have them check the front guide links' hydraulic bushings before replacing shock absorbers or ball joints.

Cost cited in the source

No verified estimate; ask the garage for a quote.A rough figure from the original database, not an up-to-date quote.

Sources from the original database

Engine / equipment

2.0 TFSI in the Audi A4 (B8), A5 (8T), Q5 (8R) and A6 (C7)

Period mentioned

2012–2014

Symptoms

Engine warning light, coolant level warning, a heater that barely warms, a higher than normal temperature and limp mode; sometimes also automatic gearbox faults.

Possible cause described

One of the coolant control valves (N82, N509 or N488) leaks, and the coolant enters the wiring harness through its connector and reaches several control units; codes P275300 or P275500 may appear in the gearbox. Audi describes it in bulletin 01 15 31 (July 2015).

Check for the garage

With a high temperature, stop and do not drive on; do not open the reservoir when hot. At the garage, have them check the coolant valves and their connectors, and whether fluid has entered the harness, before replacing control units.

Cost cited in the source

No verified estimate; ask the garage for a quote.A rough figure from the original database, not an up-to-date quote.

Sources from the original database

Engine / equipment

1.6 and 2.0 TDI (EA189 and EA288)

Period mentioned

Approx. 2010–2020

Symptoms

Coolant level drops with no visible leak, white smoke with a sweet smell, rising temperature or engine light. In severe cases the engine hydrolocks.

Possible cause described

The internal tubes of the EGR cooler crack and coolant enters the intake. It worsened after the post-Dieselgate software update, which increased EGR use.

Check for the garage

Cooling system pressure test and check for coolant in the intake or manifold.

Cost cited in the source

€400–1,300A rough figure from the original database, not an up-to-date quote.

Sources from the original database

Engine / equipment

2.7 and 3.0 TDI V6 (EA896 and EA897): Audi A4, A5, A6, A7, A8, Q5, Q7; VW Touareg, Phaeton and Amarok; Porsche Cayenne, Macan and Panamera

Period mentioned

2004–2018

Symptoms

Chain rattle for the first seconds after a cold start; power loss or limp mode from the intake flaps; coolant or oil loss in the engine V; EGR faults with rough idle.

Possible cause described

The timing chains sit at the rear of the engine, against the bulkhead, and their tensioners lose pressure. The intake flaps use plastic linkage rods that wear. The coolant valve, oil cooler gasket and EGR are packed into the engine V and leak with age.

Check for the garage

Listen to a cold start (a rattle lasting more than 2–3 seconds is a bad sign), check flap operation with a diagnostic tool, look for leaks in the engine V and check the oil change history.

Cost cited in the source

Tensioners and chains: approx. €2,000–4,500; EGR with cooler: €1,000–1,500; oil cooler gasket: €300–600A rough figure from the original database, not an up-to-date quote.

Mileage cited in the database: 100,000–150,000 km. This is not a maintenance interval and does not predict a failure.

Sources from the original database

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.

Sources from the original database

Engine / equipment

4.2 V8 40-valve (S4 B6/B7) and 4.2 FSI V8 (RS4 B7, S5 8T until 2011, RS5, R8, Q7 4L)

Period mentioned

2003–2015

Symptoms

Rattle from the rear of the engine on a cold start, misfires or an engine light for timing deviation; on FSI engines, power loss and rough idle from carbon build-up.

Possible cause described

The timing chains sit at the rear of the engine, against the bulkhead, with plastic guides and tensioners that crack; replacing them means removing the engine. FSI direct injection builds carbon on the intake valves from about 40,000–60,000 km.

Check for the garage

Listen to a cold start, read crank-cam correlation codes and inspect the intake valves with a borescope.

Cost cited in the source

Chains (engine out): approx. €6,500–11,000 on a Q7 4.2 FSI (converted from dollars); carbon cleaning: far lessA rough figure from the original database, not an up-to-date quote.

Mileage cited in the database: from 40,000 km. This is not a maintenance interval and does not predict a failure.

Sources from the original database