Audi A5 Sportback 2.0 TFSI (B8/B8.5)

The EA888 Gen 2 engines (CDNC code, 2008-2012) are widely known for excessive oil consumption caused by undersized piston ring oil return passages that clog with carbon deposits. Consumption of 0.5-1.0 litres per 1,000 km is commonly reported, typically becoming noticeable after 80,000-100,000 km. Audi considers up to 0.5 litres per 1,000 km as within specification, which many owners find unacceptable. The A5 Owner's Club forum has an extensive FAQ thread documenting this issue across hundreds of reports. Mild cases can be managed by topping up regularly at €200-400 per year in oil. Severe cases require piston and ring replacement, costing €2,500-3,500 due to the engine strip-down required. The B8.5 facelift (2012+) uses revised 21 mm wrist pin pistons and dual injection that significantly reduced this problem. When buying a pre-2012 car, always check the oil level on the dipstick and ask the seller about oil top-up frequency between services.

The EA888 Gen 2 timing chain tensioner is the most critical safety issue on pre-2012 engines. The hydraulic tensioner relies on oil pressure to keep the chain taut, and as the ratchet mechanism wears, the tensioner piston retracts when the engine is switched off. This causes a distinctive metallic rattle on cold start lasting 1-30 seconds. If the chain skips teeth, valve-to-piston contact causes catastrophic engine damage — one A5OC member reported a €15,000 engine replacement quote after chain skip at 98,000 km. Preventive replacement of the tensioner, chain, guides, and sprockets costs approximately €1,200-1,800 at an independent VAG specialist. If the chain has already skipped and caused damage, cylinder head repair runs €2,500-3,500. VW/Audi issued revised tensioner parts multiple times. The B8.5 facelift (2012+) has a notably improved tensioner that is far more durable, though not entirely immune. Cold start rattle testing is the single most important pre-purchase check.

The EA888 uses an integrated water pump and thermostat housing with a plastic body that is a well-documented failure point across the entire engine family. The seals and housing degrade from heat cycling, causing coolant leaks visible as drips or stains around the front of the engine. Symptoms include low coolant warnings, poor cabin heating, and possible engine overheating if left unaddressed. Audi issued a recall (campaign 19N4) for 2013-2017 A5 models covering the auxiliary coolant pump, which is a related but separate issue. The thermostat housing replacement costs €500-1,000 at an independent specialist, including 3-4 hours of labour. Metal impeller aftermarket replacements are more durable than the original plastic design and are recommended. This is common by 100,000 km and should be considered a near-certainty on higher-mileage cars.

All EA888 engines with direct injection only (pre-2012 Gen 2) suffer from carbon buildup on the intake valves because fuel is injected directly into the cylinder, bypassing the intake ports. Oil vapour from the PCV system bakes onto the valves over time, progressively restricting airflow. Symptoms include rough idle, cold-start misfires, hesitation under load, and reduced power, typically becoming noticeable between 80,000-120,000 km. The fix is walnut shell blasting of the intake ports, costing approximately €400-800 at a specialist in Western Europe. Some owners need this every 40,000-60,000 km on the Gen 2 engine. The B8.5 facelift (2012+) added a secondary port injection system that partially mitigates this issue by keeping the valves washed with fuel during light-load operation, making it noticeably less severe. A failed PCV valve accelerates carbon buildup, so replacing it promptly helps slow the process.

The original diverter valve uses a rubber diaphragm that degrades from heat and pressure cycling. When it tears, boost pressure escapes, causing sluggish acceleration, a hissing noise from the engine bay, and fault code P0299 for turbo underboost. The revised piston-style valve from Audi (part number 06H145710D) is far more durable and costs approximately €50-80. Labour is typically under an hour. This is one of the most common failures on the EA888, affecting the majority of cars by 100,000 km, but it is also one of the cheapest and easiest fixes. Aftermarket alternatives from Forge or GFB are popular among enthusiasts and offer even greater durability.

The PCV (Positive Crankcase Ventilation) valve contains a rubber diaphragm that is prone to tearing, typically after 80,000-120,000 km. When it fails, excessive crankcase pressure develops, pushing oil past seals and gaskets. Symptoms include oil leaks around the valve cover, rough idle, increased oil consumption, and faster carbon buildup on the intake valves. Diagnosis is straightforward: remove the oil filler cap while the engine idles — if the engine stumbles noticeably, the PCV diaphragm has likely failed. The replacement part costs approximately €40-80 and the job takes 1-2 hours, for a total of €150-350. VW/Audi has updated the PCV valve design multiple times. A failed PCV valve worsens nearly every other engine-related issue on this car, so replacing it promptly is important.

Front-wheel-drive A5 models with automatic transmission use the multitronic CVT (0AW), which has a documented reliability record of concern. Common failures include chain stretch causing jerking during acceleration (especially between 30-50 km/h), friction plate burnout, and transmission control module faults causing limp mode. Problems typically surface after 100,000 km, especially when fluid changes were neglected — Audi marketed the CVT fluid as a lifetime fill, but specialists strongly recommend changing it every 60,000 km. Gearbox controller repair costs around €800-1,200; full rebuild runs €2,000-3,500. Audi discontinued the multitronic in 2014, effectively making the A5 the last model it was sold with. Manual gearbox and quattro S-tronic models are not affected.

The DL501 (0B5) 7-speed S-tronic is the automatic for quattro A5 models. The mechatronic unit is the primary failure point, with the internal circuit board and G676 position sensor degrading from constant exposure to hot transmission oil. Early B8 models (2009-2012) are most affected. Symptoms include harsh downshifts, a forward lunge when coming to a stop, loss of reverse, EPC warning light, and gearbox malfunction warnings. Specialist mechatronic rebuilds cost €900-1,500; complete repair with labour runs €1,500-2,500. Full mechatronic replacement at an Audi dealer can reach €3,500. Regular S-tronic oil changes every 60,000 km are essential prevention — do not follow the lifetime-fill claim. Manual gearbox and multitronic-equipped cars are not affected.

The A5 B8 uses a complex multi-link front suspension with multiple aluminium control arms per side. The rubber bushings in these arms deteriorate over time, particularly in the upper control arms. Symptoms include clunking or squeaking over bumps, vague steering feel, and uneven front tire wear. This is a wear item rather than a design defect, typically appearing after 80,000-120,000 km. A complete control arm kit for both sides costs approximately €300-500 in quality aftermarket parts (Lemforder, Meyle HD). Total replacement including alignment runs €500-800 at an independent shop or €800-1,200 at an Audi dealer. Wheel alignment is required after replacement.